An In-Depth Optimization of Thickness of Base and Emitter of ZnO/Si Heterojunction-Based Crystalline Silicon Solar Cell: A Simulation Method (original) (raw)

An Investigation of High Performance Heterojunction Silicon Solar Cell Based on n-type Si Substrate

Journal of Nano- and Electronic Physics

In this study, high efficient heterojunction crystalline silicon solar cells without using an intrinsic layer were systematically investigated. The effect of various parameters such as work function of transparent conductive oxide (ϕTCO), density of interface defects, emitter and crystalline silicon thickness on heterojunction silicon solar cell performance was studied. In addition, the effect of band bending and internal electric field on solar cell performance together with the dependency of cell performance on work function and reflectance of the back contact were investigated in full details. The optimum values of the solar cell properties for the highest efficiency are presented based on the results of the current study. The results represent a complete set of optimum values for a heterojunction solar cell with high efficiency up to the 24.1 % with VOC  0.87 V and JSC  32.69 mAcm-2 .

Design of Al:ZnO/p-Si Heterojunction Solar Cell Using SCAPS Simulation Program

Journal of Nano- and Electronic Physics, 2021

ZnO thin film is a prominent candidate to be used as a buffer layer in silicon solar cells. In this paper, the effect of Al concentrations (1, 5, 10 wt. %) on the conversion efficiency of Al:ZnO/Si thin film solar cells has been investigated through simulation by SCAPS program. It has been found that the main photovoltaic parameters such as open-circuit voltage, short-circuit current density, fill factor, conversion efficiency, quantum efficiency and ideality factor increased as Al enrichment occurred. At 10 wt. % of Al the optimum conversion efficiency was approximately 7 %, the maximum value of the ideality factor was 17.51, and the bandgap value was 3.56 eV. Additionally, the resistivity, carrier concentration and mobility were determined for all measurements. It has been found that a decrease in the Hall coefficient led to an increase in the carrier concentration with increasing Al content, while an increase in the mobility occurred due to a decrease in the electrical resistivity. The quantum efficiency of the solar cell measured at a wavelength in the range of 400-1000 nm was between 0.4-0.5.

Development of Hetero-Junction Silicon Solar Cells with Intrinsic Thin Layer: A Review

Coatings

This paper presents the history of the development of heterojunction silicon solar cells from the first studies of the amorphous silicon/crystalline silicon junction to the creation of HJT solar cells with novel structure and contact grid designs. In addition to explanation of the current advances in the field of research of this type of solar cells, the purpose of this paper is to show possible ways to improve the structure of the amorphous silicon/crystalline silicon-based solar cells for further improvement of the optical and electrical parameters of the devices by using of numerical simulation method and current hypotheses. This paper briefly describes the history, beginning from the first studies of and research of HJT-structure solar cells. It raises questions about the advantages and existing problems of optimization of HJT solar cells. The authors of this paper are proposing further ways of design development of HJT solar cells.

ZnO Films with Tailored Material Properties for Highly Efficient Thin-Film Silicon Solar Modules

This study addresses the balance between electrical and optical properties of magnetron sputtered aluminum doped zinc oxide (ZnO:Al) films for the application as front contact in silicon thin-film solar cells and modules. We gradually decreased the amount of carrier concentration in the ZnO:Al films without any effect on surface topography. By reducing carrier concentration resistivity rose while parasitic free carrier absorption of the transparent conductive oxide in the near infrared decreased. The relationship between carrier concentration and short circuit current density of microcrystalline silicon (µc-Si:H) single junction thin-film solar cells has been studied experimentally. These data have been used to estimate optimal carrier concentration of the front TCO of single and multi junction modules. Besides, current enhancement by tailoring the charge carrier density, the opencircuit voltage was enhanced by in situ controlled SiH4 flow profiling during µc-Si:H deposition. In first promising results in triple junction a-Si:H / µc-Si:H / µc-Si:H modules (64 cm 2 ) we achieved an initial aperture area efficiency of 11.1%.

Electron Affinity and Bandgap Optimization of Zinc Oxide for Improved Performance of ZnO/Si Heterojunction Solar Cell Using PC1D Simulations

Electronics

For further uptake in the solar cell industry, n-ZnO/p-Si single heterojunction solar cell has attracted much attention of the research community in recent years. This paper reports the influence of bandgap and/or electron affinity tuning of zinc oxide on the performance of n-ZnO/p-Si single heterojunction photovoltaic cell using PC1D simulations. The simulation results reveal that the open circuit voltage and fill factor can be improved significantly by optimizing valence-band and conduction-band off-sets by engineering the bandgap and electron affinity of zinc oxide. An overall conversion efficiency of more than 20.3% can be achieved without additional cost or any change in device structure. It has been found that the improvement in efficiency is mainly due to reduction in conduction band offset that has a significant influence on minority carrier current.

Optical improved structure of polycrystalline silicon-based thin-film solar cell

Solar Energy Materials and Solar Cells, 2002

This paper presents an n-i-p type solar cell structure consisting of polycrystalline silicon thin film as an absorber of incident radiation and a ZnO thin film for optical improvement. The characteristics of Si layers (thickness and doping level) are designed to assure a high value of collection efficiency for photogenerated carriers. The thin films of polycrystalline silicon are obtained by CVD at a temperature of around 6201C. ZnO thin film is prepared by thermal decomposition of Zn-acetylacetonate [Zn(C 5 H 7 O 2 ) 2 ] in a vertical reactor. It is used as AR coating and as contact electrode due to its properties of high transparency (>90%) and high conductivity (3 Â 10 À4 O cm). Polycrystalline silicon and ZnO films have been investigated in terms of surface morphology and grain size by AFM and XRD. r

Optimization of Si doping in ZnO thin films and fabrication of n-ZnO:Si/p-Si heterojunction solar cells

Journal of Alloys and Compounds, 2020

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ITO-Free Silicon Heterojunction Solar Cells With ZnO:Al/SiO2 Front Electrodes Reaching a Conversion Efficiency of 23%

IEEE Journal of Photovoltaics, 2019

Silicon heterojunction solar cells (SHJ) have been increasingly attracting attention to the PV community in the last years due to their high efficiency potential and the lean production process. We report on the development of a stable baseline process for SHJ cells with a focus on the optical improvement of the solar cells' front side. An amorphous silicon oxide layer (a-SiO 2) was used as an anti-reflective coating (AR) on top of the finished SHJ devices. Both optical simulations and experimental results demonstrate a short circuit current density (J sc) improvement of 0.4 mA/cm 2 when applying the a-SiO 2 AR, yielding maximum conversion efficiencies of 23.0 %. Full-size cells with 244-cm 2 total area have been produced using three front contact stacks: ITO as reference, ZnO:Al and ZnO:Al/SiO 2 showing the J sc improvement with the double AR configuration. Damp-heat tests on those samples are currently being carried out.

Optimization of Al-Doped ZnO Transparent Conducting Oxide and Emitter Layers for Enhanced Performance of Si Heterojunction Solar Cells

Journal of Electronic Materials, 2020

Heterojunction silicon solar cells, also known as heterojunctions with intrinsic thin layer (HIT) of the type TCO/n-a-Si:H/i-a-Si:H/p-c-Si/p +-a-Si:H/BSF solar cells (where TCO is transparent conducting oxide involving Al-doped ZnO; a-Si:H is hydrogenated amorphous silicon; c-Si:H is hydrogenated crystalline silicon; BSF is back surface field, n-and prefer to n-type and p-type, respectively; n-a-Si is the emitter layer; i-a-Si is the passivation layer of intrinsic type semiconductor) have attracted special interest due to their suitability and high efficiency. Thickness and work function for the TCO layer, together with thickness and doping density of the emitter layer, are all optimized here. With optimal parameters, TCO/n-a-Si:H/i-a-Si:H/p-c-Si/p +-a-Si:H/ BSF solar cells exhibit high simulation characteristics in terms of conversion efficiency (25.62%), open circuit potential (V OC , 744 mV), short circuit current density (J SC , 42.43 mA/cm 2) and fill factor (FF, 83.7%). The Automat for Simulation of Heterostructures (AFORS-HET) program is used. The energy band diagram, current density, quantum efficiency, and charge-carrier generation/recombination behaviours are investigated to find out how heterojunction cell performance enhancement occurs.