Organic Photovoltaics Research Papers - Academia.edu (original) (raw)

A ternary blend system with two donors and one acceptor provides an effective route to improve the performance of organic solar cells. A synergistic effect of polymer and small molecules is observed in ternary solar cells, and the power... more

A ternary blend system with two donors and one acceptor provides an effective route to improve the performance of organic solar cells. A synergistic effect of polymer and small molecules is observed in ternary solar cells, and the power conversion effi ciency (PCE) of the ternary system (8.40%) is higher than those of binary systems based on small molecules (7.48%) or polymers (6.85%).

Industrially viable assembly techniques have been established for dye solar cells to be used in low light (indoor) and outdoors applications. Stability behavior under thermal stress, UV and visible light irradiation is investigated, in... more

Industrially viable assembly techniques have been established for dye solar cells to be used in low light (indoor) and outdoors applications. Stability behavior under thermal stress, UV and visible light irradiation is investigated, in particular in view of real outdoors conditions. Solid-state dye solar cells were also assembled, where an organic p-type semiconductor material replaces the currently employed liquid electrolyte.

Recently, indoor organic photovoltaics (OPVs) has attracted substantial research attention, due to the emergence of self-powered electronic devices for Internet-of-Things (IoT) applications. This progress report discusses recent... more

Recently, indoor organic photovoltaics (OPVs) has attracted substantial research attention, due to the emergence of self-powered electronic devices for Internet-of-Things (IoT) applications. This progress report discusses recent developments in indoor OPVs, focusing on the strategic role of synergistic parasitic resistance in suppressing the leakage current to achieve high indoor efficiencies. Moreover, an underexplored area is presented, namely the impact of optical modulation on enhancing light absorption in indoor OPVs. First, the main advances in material design for indoor OPVs are briefly presented. This is followed by detailed discussions of the crucial strategies, including interfacial engineering, the effect of photoactive layer thickness, and the effectiveness of transparent conducting electrodes for improving the OPV performance. Overall, this review highlights that understanding the indispensable role of parasitic resistance under dim light conditions may provide new opportunities for developing efficient indoor OPVs for practical
applications. Finally, after summarizing recent progress in indoor OPVs, a
critical perspective is provided.

The potential of a symmetrical n-hexyl substituted squaraine dye (Sq1) for use as electron donor component in bulk heterojunction organic solar cells (BHJ) with standard and inverted structure has been studied from optical point of view.... more

The potential of a symmetrical n-hexyl substituted squaraine dye (Sq1) for use as electron donor component in bulk heterojunction organic solar cells (BHJ) with standard and
inverted structure has been studied from optical point of view. The soluble n-type fullerene, (6,6)-phenyl C61 butyric acid methyl ester (PC61MB) was chosen as acceptor. Optical
modeling based on transfer matrix method was carried out to
predict photovoltaic performance of a BHJ device with blended Sq1/PC61MB active layer. It was found out that inverted device stacks show larger calculated maximum short circuit photocurrent (Jsc max) compared to the standard device structure. Modeling of the optical field distribution in the different device stacks proved that this enhancement originates from an increased absorption of incident light in the active layer, and hence from the increased exciton generation rate. Besides, it is also found that the effect of the optical spacer to the increase in Jsc max is less expressed in inverted device stacks than in standard ones.

Carbon nanotubes (CNTs) are hailed as being a "revolutionary super-material", with extensive scope of application, a highly promising one being in Organic Solar Cells (OSCs): ultrathin, ultralight and flexible solar cells with phenomenal... more

Carbon nanotubes (CNTs) are hailed as being a "revolutionary super-material", with extensive scope of application, a highly promising one being in Organic Solar Cells (OSCs): ultrathin, ultralight and flexible solar cells with phenomenal applicability and potential. This led us to investigate: "What about their structure, computerised manufacture and function gives CNT OSCs outstanding potential for application in India, what are their economic and environmental benefits and how feasible is their large-scale application in the near future?" Extensive research is done first in their manufacture, wherein the software modeling, machine 3D printing IT System for Si SCs and computerised roll-to-roll piezoelectric inkjet printing used for OSCs are evaluated. Thereafter, the functional science of both SCs is compared (with little difference found). Next, using the LCOE (Levelised Cost of Electricity) method and an interview with a spokesperson from the National Institute of Solar Energy, in depth primary and secondary economic data is collected and compared on running an Si SC and Coal Power Plant with an ideal OSC power system, which shockingly yields OSCs as being even cheaper than coal power! Finally, after discussion on India's grave environmental health and how solar power will help greatly improve that, time until and extent of OSC mass commercialisation and feasibility in India was hypothesized, based on current scientific and developmental progress as well as shortcomings that must be averted prior to this. OSCs are in fact a groundbreaking, lifesaving potential power alternative for India, owing to scope of application, environmental improvements, achieving grid parity, and outstanding reduction in the digital divide and equality of access rampant throughout the nation. It was discovered that while they are arguably the most economical power solution viable, research suggests that they are not to be commercially widespread or even available until at least the coming decade.

Main approaches to the design of organic bulk heterojunction photovoltaic structures are generalized and systematized. Novel photovoltaic materials based on fullerenes, organic dyes and related compounds, graphene, conjugated polymers and... more

Main approaches to the design of organic bulk heterojunction photovoltaic structures are generalized and systematized. Novel photovoltaic materials based on fullerenes, organic dyes and related compounds, graphene, conjugated polymers and dendrimers are considered. The emphasis is placed on correlations between the chemical structure and properties of materials. The effect of morphology of the photoactive layer on the photovoltaic properties of devices is analyzed. Main methods of optimization of the photovoltaic properties are outlined.

ABSTRACT A water-soluble cationic polythiophene derivative, poly[3-(6-{4-tert-butylpyridiniumyl}-hexyl)thiophene-2,5-diyl] [P3(TBP)HT], is combined with anionic poly(3,4-ethylenedioxythiophene):poly(p-styrenesulfonate) (PEDOT:PSS) on... more

ABSTRACT A water-soluble cationic polythiophene derivative, poly[3-(6-{4-tert-butylpyridiniumyl}-hexyl)thiophene-2,5-diyl] [P3(TBP)HT], is combined with anionic poly(3,4-ethylenedioxythiophene):poly(p-styrenesulfonate) (PEDOT:PSS) on indium tin oxide (ITO) substrates via electrostatic layer-by-layer (eLbL) assembly. By varying the number of eLbL layers, the electrode's work function is precisely controlled from 4.6 to 3.8 eV. These polymeric coatings are used as cathodic interfacial modifiers for inverted-mode organic photovoltaics that incorporate a photoactive layer composed of either poly[(3-hexylthiophene)-2,5-diyl] (P3HT) and the fullerene acceptor [6,6-phenyl-C61-butyric acid methyl ester (PC61BM) or the low bandgap polymer [poly({4,8-di(2-ethylhexyloxyl)benzo[1,2-b:4,5-b′]dithiophene}-2,6-diyl)-alt-({5-octylthieno[3,4-c]pyrrole-4,6-dione}-1,3-diyl) (PBDTTPD)] and the electron acceptor [6,6-phenyl-C71-butyric acid methyl ester (PC71BM)]. The power conversion efficiency (PCE) of the resulting photovoltaic device is dependent on the composition of the eLbL-assembled interface and permits the fabrication of devices with efficiencies of 3.8% and 5.6% for P3HT and PBDTTPD donor polymers, respectively. Notably, these devices demonstrate significant stability with a P3HT:PC61BM system maintaining 83% of its original PCE after 1 year of storage and a PBDTTPD:PC71BM system maintaining 97% of its original PCE after over 1000 h of storage in air, according to the ISOS-D-1 shelf protocol.

The excited-state properties in a series of solar cell dyes are investigated with a long-range-corrected (LC) functional which provides a more accurate description of charge-transfer states. Using time-dependent density functional theory... more

The excited-state properties in a series of solar cell dyes are investigated with a long-range-corrected (LC) functional which provides a more accurate description of charge-transfer states. Using time-dependent density functional theory (TDDFT), the LC formalism correctly predicts a large increase in the excited-state electric dipole moment of the dyes with respect to that of the ground state, indicating a sizable charge separation associated with the S1 ← S0 excitation. The performance of the LC-TDDFT formalism, illustrated by computing excitation energies, oscillator strengths, and excited-state dipole moments, demonstrates that the LC technique provides a consistent picture of charge-transfer excitations as a function of molecular size. In contrast, the widely-used B3LYP functional severely overestimates excited-state dipole moments and underestimates the experimentally observed excitations, especially for larger dye molecules. The results of the present study emphasize the importance of long-range exchange corrections in TDDFT for investigating the charge-transfer dynamics in solar cell dyes.(Received November 13 2008)(Accepted February 02 2009)

Dye sensitized solar cells (DSSCs) were fabricated with four naturally occurring anthocyanin dyes extracted from naturally found fruits/juices (viz., Indian jamun, plum, black currant, and berries) as sensitizers. Extraction of... more

Dye sensitized solar cells (DSSCs) were fabricated with four naturally occurring anthocyanin dyes extracted from naturally found fruits/juices (viz., Indian jamun, plum, black currant, and berries) as sensitizers. Extraction of anthocyanin was done using acidified ethanol. The highest power conversion efficiencies (η) of 0.55% and 0.53% were achieved for the DSSCs fabricated using anthocyanin extracts of blackcurrant and mixed berry juice. Widespread availability of these fruits and juices, high concentration of anthocyanins in them, and ease of extraction of anthocyanin dyes from these commonly available fruits render them novel and inexpensive candidates for solar cell fabrication. Anthocyanins are naturally occurring biodegradable and nontoxic molecules that are extracted using techniques that involve negligible low cost to the environment and therefore can provide ecofriendly alternatives to synthetic dyes for DSSC production.

Harnessing the sun as an energy source is of great inter- est in this age of energy crises, and holds our imagination because of its quiet, seemingly magical properties. Photo- voltaic technologies have grown quickly over the past 20... more

Harnessing the sun as an energy source is of great inter- est in this age of energy crises, and holds our imagination because of its quiet, seemingly magical properties. Photo- voltaic technologies have grown quickly over the past 20 years, and more and more applications of solar power are finding use today. In the arts, solar power is often used as energy sources for public artworks, as a practical matter. These systems typically work in conjunction with batter- ies or other sources of energy in order to ensure a constant voltage and power level. However, an alternate approach is to design the work to use the sun’s energy directly, and exclusively, with the sunlight itself as a functional param- eter of the material. In this paper, we examine the use of photovoltaics in the direct production of sound as a func- tion of its existence. These solarsonic works are designed to use the sun in the same way that wind-based artworks use the wind: they are activated directly, and are totally dependent on the light available in the moment. We sur- vey solarsonic works by several artists, and discuss a se- ries of works by the author, and conclude with a look at what the future may bring.

Abstract. Over the last three decades, progress in the organic photovoltaic field has resulted in some device features which make organic cells applicable in electricity generation configura-tions where the standard silicon-based... more

Abstract. Over the last three decades, progress in the organic photovoltaic field has resulted in some device features which make organic cells applicable in electricity generation configura-tions where the standard silicon-based technology is not suitable, for instance, when a semi-transparent photovoltaic panel is needed. When the thin film solar cell performance is evaluated in terms of the device’s visible transparency and power conversion efficiency, organic solar cells offer the most promising solution. During the last three years, research in the field has consoli-dated several approaches for the fabrication of high performance semi-transparent organic solar cells. We have grouped these approaches under three categories: devices where the absorber layer includes near-infrared absorption polymers, devices incorporating one-dimensional pho-tonic crystals, and devices with a metal cavity light trapping configuration. We herein review these approaches. © The Authors. Published by...