Photovoltaic Cells Research Papers - Academia.edu (original) (raw)

2025, Matéria (Rio de Janeiro)

RESUMO A energia solar fotovoltaica é atualmente um mercado consolidado. Entre 2010-2016, a taxa de crescimento global de instalações fotovoltaicas foi de 40%, um crescimento dificilmente alcançado por outros segmentos da indústria tecnológica. Células solares de silício responderam por 94% do mercado em 2016, enquanto a parcela referente aos filmes finos foi de 6%. Um dos materiais empregados no segmento fotovoltaico de filmes finos é o disseleneto de cobre índio e gálio (CIGS). Este trabalho apresenta os primeiros resultados de um programa colaborativo entre o Instituto Militar de Engenharia e o Florida Solar Energy Center, que visa à fabricação de células fotovoltaicas de CIGS. Os dispositivos com a configuração vidro/Mo/CIGS/CdS/ZnO/ZnO:Al/metal foram fabricados no Florida Solar Energy Center e caracterizados no Instituto Militar de Engenharia, a partir das medidas de resposta espectral e dos parâmetros fotovoltaicos extraídos das curvas corrente-tensão. A maior eficiência alcan...

2025, Angewandte Chemie International Edition

Foundation and the European Research Council (Advanced Grant no 247404 to M.G.) is gratefully acknowledged. We thank Dr. Carole Grätzel for valuable discussions and editorial help with the manuscript. We also thank Prof. S. Ito and Prof.... more

2025, Journal of Physical Chemistry C

2025, ACS Sustainable Chemistry & Engineering

Fullerene-free all-small-molecule organic photovoltaic cells (SM-OPVs) have attracted considerable attention because of well-defined molecular structures with low batch-tobatch variation. Porphyrin derivatives are recently emerged as one of promising conjugated building blocks for the small-molecule (SM) donors. Herein, we first report fullerene-free SM-OPVs employing porphyrin-based donors. Three zinc porphyrin (P Zn )-based SM donors, which have strong bimodal absorption in visible region and near infrared region, are synthesized. Constructing bulk-heterojunction (BHJ) active layers using the P Zn donors and a SM acceptor, IDIC, which have complementary absorption, achieved panchromatic photon-to-currentconversion from 400 to 900 nm. The manipulation of side chains in the P Zn donors considerably influenced the molecular ordering and nanomorphology of the BHJ active layers. The P Zn based fullerene-free SM-OPV devices with a promising power conversion efficiency of 6.13% was achieved, which also offers a crucial guidance for developing fullerene-free OPVs using porphyrin derivatives.

2025

En el contexto mundial se vive un auge en la investigación de la movilidad eléctrica. Cada día toma más importancia el desarrollo de estas tecnologías debido a la necesidad de un sistema que emplee energías sustentables sin prescindir de las libertades a las que nos han acostumbrados los sistemas de movilidad actual. En este artículo se describe de manera conceptual el proceso de investigación, diseño y ensamble del prototipo de una bicicleta eléctrica, las soluciones encontradas a los problemas asociados durante las diferentes etapas del prototipo y por último se presenta el análisis de los resultados obtenidos durante las pruebas al prototipo. Creative Commons Licenses NC UPB 2014

2025

Datasets of various levels of solar cell shunt resistances were available in the literature, resulting in a linear correlation to forecast shunt resistance (R sh ) degradation and failures in photovoltaic (PV) cells. However, some PV failures initiate mildly with one or few cells in a PV module and then distribute to other cells which leads to a major power reduction as well as critical safe operation. Simulating these experimental datasets gives the potential to catch these unparalleled degradations in PV modules at early stages, preventing them from turning critical. In response, SPICE simulation was used to study the effect of PV cells with low shunt resistance in a PV module. The simulation follows four steps, focusing on the electrical output of Current-Voltage (I-V) curve of the solar cells: (a) simulation of the experimental healthy I-V curve of a PV cell; (b) simulation of experimental eleven I-V curves at reduced levels of shunt resistance; (c) simulation of a PV module by using the simulation parameters obtained from the former steps; and (d) lastly, simulation of four different scenarios depending on the number of faulty cells in a PV module. The effect of these scenarios on the I-V curve parameters is compared. Results revealed it is feasible to detect unparalleled degradations, spotting the failed cells (reduced R sh ) in a PV module by implementing a linear model correlating open-circuit voltage (V OC ) with short-circuit-current (I SC ) (acting as a proxy of Irradiance) at different shunt resistance levels. This model can be simulated as a robust indicator of PV abnormalities and is appropriate for employment in online PV monitoring systems.

2025, International Journal of Applied Power Engineering (IJAPE)

An optimal control of a grid-connected solar-wind hybrid scheme for the electricity generation system by utilizing both wind and solar renewable energy in a remote region that is inaccessible to the electricity grid. The control and assessment of a hybrid sustainable energy generation system power system that supplies three-phase, four-line loads as well as a battery array are presented in this research work. Wind energy conversion system (WECS) is comprised of a doubly-fed induction generator (DFIG) and two pulse width modulation (PWM) voltage source converters, namely the grid side converter (GSC) and the rotor side converter (RSC), which are linked together via a DC-link and are equipped with a technique for maximum power point tracking (MPPT). The grid voltage-oriented control strategy is employed to provide a consistent DC-bus voltage for the GSC and to regulate the reactive power on the power grid. Even the difference in voltage and frequency can be controlled with this novel strategy. The stator voltage-oriented vector technique is designed in the RSC control strategy, resulting in effective regulation of reactive and active power at the stator as well as an MPPT obtained by controlling the optimal torque. The hybrid sustainable energy generating system (HSEGS) simulation model is designed to have a capacity of 5 kW, and its efficiency is evaluated using the MATLAB/ Simulink platform and demonstrated in a variety of circumstances.

2025

Allwood, G. A., Wild, G., & Hinckley, S. ( ). Photovoltaic micro-cell design for distrubuted power in sensor networks.

2025

CIES2020: As Energias Renováveis na Transição Energética: Livro de Comunicações do XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia Solar. Helder Gonçalves, Manuel Romero (Ed.). Lisboa, Portugal: LNEG, 3-5 Novembro,... more

2025, Ingeniería y Desarrollo - Universidad del Norte

The presence of photovoltaic solar plants to produce electricity implies the reduction of the use of fossil fuels, and of polluting emissions. The availability of solar energy depends on weather conditions, so the parameters of the electrical energy to be delivered could be affected. The objective of this research is to present a methodology based on data science for the evaluation of the energy quality of photovoltaic solar plants connected to the grid, considering current standards. It is applied to a 260 kWp plant of the National Institute of Standards and Technology of the United States. The parameters used are total harmonic distortion, voltage fluctuations and unbalance, electrical frequency, and power factor. Almost 100% of the records comply with the limits established by the standards for the parameters, except for power factor, with 63.56%. From the power factor classification model, the knowledge that apparent and active power, and frequency, are the most important variables was gathered. From the subgroup discovery algorithm, that solar irradiance appears in 40% of the subgroups, and frequency in 50%.

2024, MDPI eBooks

Photo courtesy of Mingxiao Ye, Dongyan Zhang and Yoke Khin Yap Articles in this volume are Open Access and distributed under the Creative Commons Attribution license (CC BY), which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. The book taken as a whole is

2024

One of the main problems of renewable energies is storage of the energy carrier. For long-term storage, solar fuels seem to be a good option. Direct solar water splitting could play an important role in the production of these solar fuels. One of the main challenges of this process is the charge separation and collection at the interfaces. The knowledge on photovoltaic (PV) junctions can be used to tackle this challenge. In this work, the use of doped layers to enhance the electric field in an a-SiC:H photocathode, and the use of thin-film silicon multijunction devices to achieve a stand-alone solar water splitting device are discussed. Using a p-in structure as a-SiC:H photocathode, a current density of 10mA/cm 2 is achievable. The p-in structure proposed also indicates the suitability of traditional PV structures for solar water splitting. In addition, hybrid devices, including a silicon heterojunction PV device, are proposed. A combination of the a-SiC:H photocathode with a nc-Si:H/c-Si is demonstrated and potential STH efficiencies of 7.9% have been achieved. Furthermore, a purely PV approach such as a triple junction a-Si:H/nc-Si:H/nc-Si:H solar cell is demonstrated, with solar-to-hydrogen (STH) efficiencies of 9.8%.

2024, Advanced Sustainable Systems

The benefit of two‐terminal multijunction solar cells in regard to the number of junctions (subcells) is critically evaluated. The optical and electrical losses inherent in the construction of multijunction cells are analyzed using information from thin‐film silicon photovoltaics as a representative case. Although the multijunction approach generally reduces the thermalization and nonabsorption losses, several types of losses rise with the number of subcells. Optical reflection and parasitic absorption are slightly increased by adding supporting layers and interfaces. The output voltages decline because of the tunnel recombination junctions, and more importantly of the illumination filtered and reduced by the top subcell(s). The loss mechanisms consume the potential gains in efficiency of multijunction cells. For thin‐film silicon, the triple‐junction is confirmed to be the best performing structure. More generally, only when each component subcell shows a high ratio between the out...

2024, International Journal of Electrical Components and Energy Conversion

Alternative energy sources already today can satisfy human needs for energy. A spectrum of natural sources different from region to region. Intensity sunlight and a wind, existence or absence of water energy, geothermal sources, wood potential, quality soil and quantity of dropping out deposits for cultivation of a biomass influence a choice of that combination in which kinds of renewed energy in this or that country will be combined. From here follows, which energy needs in various regions should be satisfied with various ways.

2024, Tecnura

RESUMEN El aumento en la frecuencia de eventos hidrometeorológicos extremos, asociados a la varia

2024

In this work, the implementation of state observers in an integrated platform combining Matlab®, Simulink® and Arduino® is carried out, by means of which the state variables of an electronic converter can be accurately estimated. The plant is emulated in Matlab-Simulink, while the observers are implemented in Arduino. For this purpose, three types of observers are designed: the Luenberger observer, the Kalman filter and the sliding mode observer, for a DC-DC boost converter. The results are evaluated, allowing to highlight their advantages and disadvantages for obtaining the state variables of the converter. The methodology used has proved to be easily reproducible, which opens the possibility of future research and practical applications in the field of power electronics and control.

2024, Donald N. Tedom

Accurate prediction of solar radiation is crucial for enhancing the efficiency of renewable energy systems, agriculture, and climate studies, leading to sustainable energy solutions. This project aims to find the best machine learning and deep learning models for predicting solar radiation across ten regions in Cameroon. The models used include Linear Regression (LR), Decision Tree (DT), Random Forest (RF), Gradient Boosting Machine (GB), K-Nearest Neighbours (KNN), Long Short-Term Memory (LSTM), Artificial Neural Network (ANN), Feedforward Neural Network (FNN), Recurrent Neural Network (RNN), and Convolutional Neural Network (CNN). Using data spanning 20 years from NASA's MERRA-2 (2002-2021) and assessing metrics such as R² (0.720 to 0.957), RMSE (0.246 to 1.498 KJ/m²), rRMSE, MBE, MABE (0.131 to 1.104 KJ/m²), t-statistic, MAE, and MSE, the study found significant variability in model performance. Based on these metrics, KNN and RF were the best-performing machine learning models, while CNN was the best among deep learning models, providing reliable predictions with lower errors. For making solar radiation predictions in Cameroon, KNN, RF, and CNN are the recommended models to use.
Keywords: Solar Radiation Forecasting, Machine Learning, Cameroon, Renewable Energy, Model Comparison, Prediction Accuracy.

2024, Organic Letters

The nitration of 4,7-dibromo-2,1,3-benzothiadiazole was modified by using CF 3 SO 3 H and HNO 3 as the nitrating agent, and the related yield was improved greatly. On the basis of this improvement, two new small band gap polymers, P1TPQ and P3TPQ, were developed. Bulk heterojunction solar cells based on P3TPQ and [6,6]-phenyl-C 71 -butyric acid methyl ester exhibit interesting results with a power conversion efficiency of 2.1% and photoresponse up to 1.1 µm.

2024, Organic Electronics

Different mixtures of identically substituted C60 and C70 based fullerens have been used as acceptors in three polymer:fullerene systems that strongly express various performance limiting aspects of bulk heterojunction solar cells. Results are correlated with, and discussed in terms of e.g. morphology, charge separation, and charge transport. In these systems, there appears to be no relevant differences in either mobility or energy level positions between the identically substituted C60 and C70 based fullerenes tested. Examples of how fullerene mixtures influence the nano-morphology of the active layer are given. An upper limit to the open circuit voltage that can be obtained with fullerenes is also suggested.

2024

Orientador: José Alexandre DinizDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: Este trabalho apresenta o desenvolvimento de células fotovoltaicas de junção n+/p em substratos de Si com processos de fabricação totalmente compatíveis com a tecnologia CMOS (Complementary Metal Oxide Semiconductor). Os processos compatíveis desenvolvidos neste trabalho sao as técnicas: i) de texturização da superfície do Si, com reflexao da superficie texturizada de 15% obtida com a formação de micro-pirâmides (alturas entre 3 e 7 ?m), utilizando-se solução alcalina de NH4OH (hidróxido de amônia), que e livre da contaminação indesejável por íons de Na+ e K+ quando se utiliza soluções tradicionais de NaOH e de KOH, respectivamente, e ii) de deposição ECR-CVD (Electron Cyclotron Resonance - Chemical Vapor Deposition) da camada antirrefletora (ARC) de SiNX (nitreto de silício), que e executada em temperatura ambiente, portanto pode ser fe...

2024, IEEE Transactions on Nanotechnology

Arrays of periodic one-dimensional nanomaterials offer tunable optical properties in terms of light-matter interaction which are attractive for designing efficient optoelectronic devices. This paper presents a fabrication of bottom-up grown nanopillar (NP) array solar cells based on n-i-p thin-film amorphous silicon using scaffolds of vertically aligned carbon nanotube (CNT) array. The effects of varying the CNT spacing over the range from 800 to 2000 nm on optical and electrical properties of the solar cells were investigated. The NP solar cell with CNT spacing of 800 nm exhibited 'moth-eye' broadband antireflection behavior, showing an average reflectance value lower than 10%. The enhanced optical absorption translated to significant enhancements in photocurrent and quantum efficiency compared to a conventional planar solar cell under low light condition. The open-circuit voltage (V o c) of the NP solar cell was found systematically correlated with the CNT spacing and the illumination condition. The results presented here is of importance for developing high efficiency one-dimensional nanostructured solar cells. Index Terms-Amorphous silicon, carbon nanotube (CNT), nanophotonics, nanostructured materials, photovoltaic cells. I. INTRODUCTION I NTERACTION of light with spatially ordered nanostructures exhibits some unique characteristics, particularly when the features sizes are in the order of the incident wavelength. Exploiting these properties to enhance the absorption of solar cells has been an active research topic over the last few years

2024

Single converter solar high mast lighting system is a project to design and implement a stand-alone MIMO converter solar power high mast light. The main focus of this project is to determine the options that are available to replace grid-powered street lamps with a stand-alone system that has the reliability to work under the worst conditions. The system's main circuit is a MIMO converter which is able to accommodate arbitrary number of sources and loads. The system consists of two inputs and outputs i.e. inputs as solar cell and power grid and outputs as battery and high mast light. It only employs a single inductor, which can reduce the complexity and cost of the system as well as simplify the current sensing. By sensing the inductor current and monitoring the switching signals of the switches, the input and output currents can be determined without employing additional current sensing circuitry.

2024

You may also like Recent advances in non-fullerene organic photovoltaics enabled by green solvent processing Shilin Li, Hong Zhang, Shengli Yue et al.-Achieving efficient and stable organic solar cells by using polyethylene glycol to... more

2024, Energies

We analyze the output of various state-of-the-art irradiance models for photovoltaic systems. The models include two sun position algorithms, three types of input data time series, nine diffuse fraction models and five transposition models (for tilted surfaces), resulting in 270 different model chains for the photovoltaic (PV) system simulation. These model chains are applied to 30 locations worldwide and three different module tracking types, totaling in 24,300 simulations. We show that the simulated PV yearly energy output varies between −5% and +8% for fixed mounted PV modules and between −26% and +14% for modules with two-axis tracking. Model quality varies strongly between locations; sun position algorithms have negligible influence on the simulation results; diffuse fraction models add a lot of variability; and transposition models feature the strongest influence on the simulation results. To highlight the importance of irradiance with high temporal resolution, we present an analysis of the influence of input temporal resolution and simulation models on the inverter clipping losses at varying PV system sizing factors for Lindenberg, Germany. Irradiance in one-minute resolution is essential for accurately calculating inverter clipping losses.

2024, Energy & Environmental Science

Tailoring the interface energetics between a polymeric hole extraction layer (HEL) and a photoactive layer (PAL) in organic photovoltaics (OPVs) and organic–inorganic hybrid perovskite solar cells (PrSCs) is very important to maximize... more

2024, Advanced materials (Deerfield Beach, Fla.)

Bright organic/inorganic hybrid perov-skite light-emitting diodes (PrLEDs) are realized by using CH3 NH3 PbBr3 as an emitting layer and self-organized buffer hole-injection layer (Buf-HIL). The PrLEDs show high luminance, current efficiency, and EQE of 417 cd m(-2) , 0.577 cd A(-1) , and 0.125%, respectively. Buf-HIL can facilitate hole injection into CH3 NH3 PbBr3 as well as block exciton quenching.

2024, Journal of the American Chemical Society

* Zn-TPP thick-layers on Si(111) * Double layer Zn-TPP/C 70 /Si(111) * Multilayer co-deposited Zn-TPP/C 70 2) Electronic structure via NEXAFS and photoemission * Same systems as above * Evidence for interaction between C 70 and Zn-TPP 3) Charge-transfer time scale with resonant photoemission *Same systems as above *In mixed systems the excited electrons are delocalized more efficiently

2024, Journal of the American Chemical Society

Record-setting organic photovoltaic cells with PTB polymers have recently achieved ∼8% power conversion efficiencies (PCE). A subset of these polymers, the PTBF series, has a common conjugated backbone with alternating thieno[3,4-b]thiophene and benzodithiophene moieties but differs by the number and position of pendant fluorine atoms attached to the backbone. These electron-withdrawing pendant fluorine atoms fine tune the energetics of the polymers and result in device PCE variations of 2−8%. Using near-IR, ultrafast optical transient absorption (TA) spectroscopy combined with steady-state electrochemical methods we were able to obtain TA signatures not only for the exciton and charge-separated states but also for an intramolecular ("pseudo") charge-transfer state in isolated PTBF polymers in solution, in the absence of the acceptor phenyl-C 61-butyric acid methyl ester (PCBM) molecules. This led to the discovery of branched pathways for intramolecular, ultrafast exciton splitting to populate (a) the charge-separated states or (b) the intramolecular charge-transfer states on the subpicosecond time scale. Depending on the number and position of the fluorine pendant atoms, the charge-separation/transfer kinetics and their branching ratios vary according to the trend for the electron density distribution in favor of the local charge-separation direction. More importantly, a linear correlation is found between the branching ratio of intramolecular charge transfer and the charge separation of hole−electron pairs in isolated polymers versus the device fill factor and PCE. The origin of this correlation and its implications in materials design and device performance are discussed.

2024, Journal of Physics: Conference Series

The hybrid integration of small-scale wind and solar energy conversion systems can be used for on- and off-grid applications. This paper investigates a stand-alone off-grid application of a hybrid small-scale wind turbine and photovoltaic (PV) cell microgrid to supply houses in rural Iraq far from the utility grid. Experimental investigations were performed to measure wind speed and solar radiation, as well as the DC voltage in the rectifier section of a small-scale permanent magnet synchronous generator (PMSG) wind turbine and the DC voltage in a PV cell for 24 hours. The results showed that using a small-scale hybrid wind and solar generating system for off-grid applications in Iraq is possible if the components are equipped with proper charge controllers that perform maximum power point tracking (MPPT) during wind speed and solar radiation fluctuations.

2024, ANZIAM Journal

Rooftop solar photovoltaic panels, household electrical energy storage (batteries), home energy management, interval metering and new tariffs will change the way that households use electricity from the grid. Distributed storage can give electricity retailers the ability to shift loads in response to changes in the wholesale price of electricity and constraints on the distribution network. What is the ideal mix of photovoltaic, storage and tariff for a customer? What is the value of these technologies to customers and to electricity retailers? In this paper we develop an algorithm that can help the customer size the photovoltaic panels and the battery to be installed, as well as choose which tariff structure would best suit them.

2024, Applied Physics Letters

2024, The journal of physical chemistry letters

Hybrid organic-inorganic perovskite crystals have recently become one of the most important classes of photoactive materials in the solar cell and optoelectronic communities. Albeit improvements have focused on state-of-the-art technology including various fabrication methods, device architectures, and surface passivation, progress is yet to be made in understanding the actual operational temperature on the electronic properties and the device performances. Therefore, the substantial effect of temperature on the optoelectronic properties, charge separation, charge recombination dynamics, and photoconversion efficiency are explored. The results clearly demonstrated a significant enhancement in the carrier mobility, photocurrent, charge carrier lifetime, and solar cell performance in the 60 ± 5 °C temperature range. In this temperature range, perovskite crystal exhibits a highly symmetrical relaxed cubic structure with well-aligned domains that are perpendicular to a principal axis, t...

2024, Journal of Nanoscience and Nanotechnology

In order to improve the dispersion of single-wall carbon nanotubes in a matrix of poly(3-hexylthiophene), this paper reports the modification of single-wall carbon nanotubes with COOH groups followed by reaction with cysteamine that introduced thiol groups along the tubes. The resulting modified single-wall carbon nanotubes were characterized by high resolution transmission electron microscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and Raman spectroscopy. The modified carbon nanotubes were applied, in combination with poly(3-hexylthiophene), in a bulk heterojunction solar cell. After passing through a post-treatment process to obtain debundled modified single-wall carbon nanotubes, solar cells with improved performance were obtained. After the treatment sequence, both the open circuit voltage and short-circuit current increased in comparison to the non-treated modified single-wall carbon nanotubes polymer solar cells.

2024

1re-built the prototype machine to the point it was ready to go into a trial mode, however after Clark Machine Inc., took the contract. to build me four machines they wanted the prototype in their yard so they could build from it. They have built one machine complete and have almost all the parts to the other three built ready to assemble. I have inspected the one that is complete and so far everything looks fine, however the engineer needs to come back and check it out and stamp the drawings. Then comes OSA to inspect the machine. After all this I feel that we have a machine that is not only good in its field it ,will sell to contractors and firms that sell this type of equipment, after. all this is done we will contract for a truck and start to test the machine, in this way if there are any mistakes we can 'correct all four machines befo"Winishiing them I have already started a complete method to contact these people, as a mater I sent out 10 last week and will keep sending out feelers until I hit someone who will appreciate what we have and sign a contract to handle the machine for us on a dealership with us.

2024

Abstract— To adapt the voltage levels and to control the energy between the storage elements and the other equipment of an electric vehicle, DC/DC power converters must be interposed. This paper focuses on the modeling and performance comparison between boost converter topologies interfacing a lithium battery and DC link. The design of classic boost converter (BC), interleaved boost converter (IBC) and Interleaved Double Dual Boost converter (IDDBC) is proposed. Simulation results that have been reached put emphasis on the advantages of the IDDBC.

2024, Physics Letters A

In this study, we report the observation of memory effect in TiO 2-GO nanocomposite films. Electrical properties of the prepared Al/TiO 2-GO composite/ITO devices have shown stable and reproducible bipolar resistive switching behavior. The TiO 2-GO composite films were prepared using solution method by spin coating technique. Observed results have shown that the inclusion of GO in the TiO 2 matrix have exhibited a significant role in the resistive switching mechanism. The device has exhibited an excellent memory characteristic with low operating voltages, good endurance up to 10 5 cycles and long retention time more than 5 × 10 3 s.

2024, Advanced Science

based energy storage technologies have been explored meet the demand in these applications. [7,12-17] Currently, the electrochemical based energy storage is largely based on Li ions batteries (LIBs), sodium ion batteries, or zinc-air batteries. [13-15,18-21] In particular, LiBs offer high energy density (≈500 W h kg −1) and benefit from well-developed manufacturing processes. [14,18,19] But majority of them are not flexible and their weight, low power density, long charging time (1-2 h), heat generation, [22] environmental concerns, [18,19,22,23] etc. limit their use in applications such as wearable systems. These limitations have already caught the attention of the research community, as evident from various works on flexible/stretchable batteries [12,13,24,25] and supercapacitors (SCs) with long cycling stability. [26-28] In particular, the SCs offer excellent energy and power densities with low-cost of fabrication. [26-31] Further they offer rapid charging (minutes vs hours in LiBs), long life cycle, do not generate heat [26,30] and are generally environment friendly. [28,29] With flexible and stretchable form factors, SCs can also conform to curved surfaces. [28] Among various types of SCs, the electrochemical double layer capacitors (EDLCs) [28,29] based on carbon materials are the most promising [28-32] because of their long lifetime (more than 10 6 charging/discharging cycles), low environmental impact, ease of maintenance, and flexible form factors. [26,27,30] The performance of SCs is mainly governed by their structure, surface morphology, electrolytes, and the electrochemical and electrical properties of active electrodes. [26,30,33-35] For this reason, the choice of electrode materials and the electrolyte are critical. Since the energy storage (areal energy density, E A = C A V 2 /2) depends on the potential window (V) and the specific capacitance (e.g., areal capacitance C A), researchers have focused on the ways to improve these values. [35-38] For example, a variety of carbon-based structures (e.g., graphene foam, [35] reduced graphene oxide (rGO), [36] etc.) have been explored for EDLC fabrication. The choice of electrolyte is also important to increase the V and hence the energy density. [37] Table S1 in the Supporting Information provides a comparison of C A , and V for EDLCs developed with various active carbonbased materials. The low values of C A (<10 mF cm −2) reported in the majority of the SCs can be attributed to the lack of electroactive surface per unit area needed to store the charge at the electrode-electrolyte interface. [33,38] The electrodes with multilayer structures have been explored to overcome such issues Energy autonomy is critical for wearable and portable systems and to this end storage devices with high-energy density are needed. This work presents high-energy density flexible supercapacitors (SCs), showing three times the energy density than similar type of SCs reported in the literature. The graphene-graphite polyurethane (GPU) composite based SCs have maximum energy and power densities of 10.22 µWh cm −2 and 11.15 mW cm −2 , respectively, at a current density of 10 mA cm −2 and operating voltage of 2.25 V (considering the IR drop). The significant gain in the performance of SCs is due to excellent electroactive surface per unit area (surface roughness 97.6 nm) of GPU composite and high electrical conductivity (0.318 S cm −1). The fabricated SCs show stable response for more than 15 000 charging/ discharging cycles at current densities of 10 mA cm −2 and operating voltage of 2.5 V (without considering the IR drop). The developed SCs are tested as energy storage devices for wide applications, namely: a) solarpowered energy-packs to operate 84 light-emitting diodes (LEDs) for more than a minute and to drive the actuators of a prosthetic limb; b) powering high-torque motors; and c) wristband for wearable sensors.

2024, The Journal of Physical Chemistry C

Water-soluble poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is the most prominent commercial polymer used in photovoltaic cells and thermoelectric devices. Experimental studies in the last decade have shown that it is possible to enhance the low electrical conductivity of PEDOT:PSS by solvent treatment, either in-solution or by post-treatment methods. The origin and mechanism of electrical conductivity improvement varied according to different experimental studies. We had recently shown that phase separation of PEDOT:PSS is key to the electrical conductivity enhancement, where dissolution of insulating PSS shell results in the release of conducting PEDOT grains for aggregation. In this study, we demonstrated that dimethyl sulfone (DMSO 2) which is a nontoxic, water-soluble, edible organic molecule, can be a greener alternative to the widely used dimethyl sulfoxide (DMSO) for solvent treatment of PEDOT:PSS chains, via a combined experimental and multiscale molecular modeling approaches. Moreover, crystalline DMSO 2 nanowire surfaces remain in the PEDOT:PSS films act as a template for the self-alignment of PEDOT chains that enhance the electrical conductivity further.

2024, Journal of physics

Deriving energy from plant has generated new technologies that are impressive. The success of harnessing energy in plants means that a global challenge has been truly solved. In this paper, the focus was to improve upon the plasmon technology in converting light to electricity such as photovoltaic. A metallic coated plant extract (MCPE) was synthesized and characterized in an unusual characterization setup to determine the basic properties required for the plasmon technology. The MCPE was found to have band gap of 3.15 eV and possesses the basic properties of electron clouds oscillating about a mean position. This result means that the MCPE is a bio-particulate option that can replace the inorganic nanoparticles in the plasmon experiment. Further work on testing the MCPE in plasmon setup is recommended.

2024, International Journal of Electrical and Computer Engineering (IJECE)

In this case study, two polycrystalline solar modules were installed outdoors (irradiated by sunlight) and indoors (irradiated by artificial lights). The solar cells in both cases were installed using different color filters that allowed the passage of certain light frequencies. The amount of energy produced by each module were measured and compared to a reference module with no filter. The results indicated the variable response of polycrystalline solar cells to natural and artificial light sources, being more responsive in both cases to red band color as could be deduced from their % current outputs (72.5% sunlight radiation; 84.38% artificial light sources). Other colors, including yellow, green, orange and violet afforded acceptable outputs. The results indicated that electrical outputs of indoor solar cells decreased when colored filters were used, but red filter in general afforded the maximum outputs, for both the artificially radiated indoor and naturally radiated outdoor solar cells. The case study suggests the possible complementary advantage of using indoor mounted solar cells for the production of electricity during artificial illumination period of the day.

2024, Anales De La Universidad Metropolitana

The theory of Sliding Mode Control (SMC) is a component of nonlinear systems theory and consists of switched or discontinuous control signals through sliding surfaces. The theory has properties of invariability with respect to the uncertainties and disturbances; however, it has the disadvantage of chattering in the control signal. On the other hand, a fuzzy controller, is based on the fuzzy set theory and the fuzzy logic. The fuzzy control, allows to transform a linguistic strategy of control, in a strategy of automatic control. In this paper we propose a design methodology that integrates sliding mode control and fuzzy control, in an original manner. We have called the technique Sliding Mode Fuzzy Control (SMFC) and it is used for the synthesis of controllers for nonlinear dynamical systems affine in the control signal. The technique solves the tracking problem of a reference trajectory and correct the disadvantages associated to the sliding mode control and fuzzy theories when they act individually.

2024, Redes de Ingeniería

El presente documento presenta el resultado parcial de la investigación acerca de las tecnologías de celdas solares multijuntura para uso espacial. Asimismo, se presenta una recopilación de los pasos que se han seguido hasta la fecha en el diseño de un prototipo de paneles fotovoltaicos de acuerdo a los requerimientos físicos, eléctricos y financieros del picosatélite Cubesat Colombia 1 de la Universidad Distrital Francisco José de Caldas.

2024

Urban population is increasing but urban transportation infrastructures have not developed in conformity with this increase which leads to high ingestion in streets. The most applied approach for solving this problem is efficient use of these infrastructures and efficient use of traffic has important role in this efficiency. Purpose of this research is presenting a factor-oriented system for controlling urban traffic control. Traffic control system can hardly have a complete and correct view of traffic in network because of distributing urban traffic along with urban transportation network and its rapid fluctuations. This needs installing sensors throughout network and sending to one center which has great cost. Therefore, agents should be able to decide regarding local information from observed area. This decision making should be in respect of meeting general purpose which is optimized traffic control. Regarding limitations, traffic control problem is modeled as resources reactive...

2024, Revista Facultad De Ingenieria

Resumen en un microinversor fotovoltaico de dos etapas con conexión a red, y el diseño de los controladores respectivos. La idea es obtener el modeló que permita operar como fuente de corriente y a su vez permita regular la tensión de entrada, con base en señal resultado del algoritmo de localización del punto de máxima potencia. Dicho esquema de control es novedoso y ha sido documentado por algunos autores utilizando convertidores tipo boost. Por lo tanto, el gran aporte del presente artículo, radica en la utilización de este novedoso esquema para aprovechar la máxima energía proveniente de los paneles, empleando un convertidor que posee la característica de aislar galvánicamente la generación del resto del circuito. Para validar el PSIM TM. Finalmente se presentan las conclusiones.

2024, Eurocon 2013

this paper presents the modeling and simulation of a Microgrid with three power sources and along with a battery as a storage system. The renewable sources are solar photovoltaic, fuel cell and wind turbine. The objective of this paper is to describe useful model of integration of non renewable sources and how the Microgrid performs accordingly along with a comparison in between output of Microgrid and the output with power quality improved. The modeling of the full system including all the stages is performed using MATLAB and SIMULINK software package. The Microgrid, for general analysis is connected to a load and is analyzed. The Microgrid operated appropriately where the settling time is considered as 2e-6.

2024

Se aplica la metodologia de analisis de varianza(ANOVA) y de la prueba de Tukey a un conjunto de datos de irradiacion solar sobre el plano de los modulos fotovoltaicos y los correspondientes valores de potencia entregada a la red electrica. Las mediciones fueron realizadas en intervalos de tiempo de 10 minutos, desde la salida hasta la puesta del sol durante las 52 semanas del ano 2013. Estos datos se obtienen a traves de un sistema de monitorizacion, ubicado en una central fotovoltaica de 10 MW de potencia nominal en Cordoba, que consta de 16 centros de transformacion y 98 inversores. La aplicacion del metodo comparativo, entre las medias del indice de comportamiento de los centros de transformacion, permite detectar con un analisis de varianza, si existe diferencia significativa en al menos un valor medio respecto al resto, a un nivel de significacion del 5% y posteriormente mediante la prueba Tukey, determinar cual o cuales son los centros de transformacion que estan por debajo d...

2024, Revista de la Facultad de Ingeniería Universidad Central de Venezuela

Este artículo presenta un análisis experimental de la sensibilidad de un algoritmo de estimación de la norma inducida L 2 especialmente diseñado para sistemas lineales conmutados. En particular, se analiza el efecto observado sobre el comportamiento del algoritmo con respecto a variaciones en el número de subfunciones, en el número de modos conmutados y en parámetros físicos característicos de cada modo. Para el análisis se seleccionaron tres modelos de prueba con diferentes grados de complejidad. Los resultados obtenidos permiten avanzar en la comprensión de dos aspectos fundamentales del algoritmo: la selección de un número de subfunciones adecuado y el significado físico de la cota de aproximación obtenida.

2024, Solar Energy Materials and Solar Cells

In this study, a gold (Au) nanomesh layer was manufactured on an ITO-coated glass substrate at room temperature. The Au nanomesh was used to induce surface plasmon resonance (SPR) to enhance the photocurrent of a polymer solar cell. The Au nanomesh was manufactured by lift-off on closely packed PS nanospheres (diameter 50 nm; density 10 10 /cm 2). The PS nanospheres were fabricated by modified block copolymer nano-patterning on ITO. A transmittance-reflection-absorbance spectrum was used to explore the induced surface plasmon. An extinction peak was observed at 580 nm indicate the possibility of Au nanomesh induced surface plasmon resonance. The short-circuit current density of the polymer solar cell was enhanced from 7.02 to 14.2 mA/cm 2 by the addition of Au nanomesh. Consequently, the power conversion efficiency enhanced from 1.9% to 3.2%. By the normalized input photon-to-current conversion efficiency (IPCE) measurement, enhanced photocurrent conversion efficiency at approximately 580 nm was observed that coincided with the extinction spectrum, indicating that the surface plasmon enhanced the photocurrent.

2024, IEEE Access

This article presents a novel asymmetrical 21-level multilevel inverter topology for solar PV application. The proposed topology achieves 21-level output voltage without H-bridge using asymmetric DC sources. This reduces the devices, cost and size. The PV standalone system needs a constant DC voltage magnitude from the solar panels, maximum power point tracking (MPPT) technique used for getting a stable output by using perturb and observe (P&O) algorithm. The PV voltage is boosted over the DC link voltage using a three-level DC-DC boost converter interfaced in between the solar panels and the inverter. The inverter is tested experimentally with various combinational loads and under dynamic load variations with sudden load disturbances. Total standing voltage with a cost function for the proposed MLI is calculated and compared with multiple topologies published recently and found to be cost-effective. A detailed comparison is made in terms of switches count, and sources count, gate driver boards, the number of diodes and capacitor count and component count level factor with the same and other levels of multilevel inverter and found to be the proposed topology is helpful in terms of its less TSV value, devices count, efficient and costeffective. In both simulation and experimental results, total harmonic distortion (THD) is observed to be the same and is lower than 5% which is under IEEE standards. A hardware prototype is implemented in the laboratory and verified experimentally under dynamic load variations, whereas the simulations are done in MATLAB/Simulink.

2024, Energy & Environmental Science