Papers by Keyword: Thin Film Solar Cell

Abstract: The performance of the InGaN single-junction thin film solar cells has been analyzed numerically employing the Solar Cell Capacitance Simulator (SCAPS-1D). The electrical properties and the photovoltaic performance of the InGaN solar cells were studied by changing the doping concentrations and the bandgap energy along with each layer, i.e. n-and p-InGaN layers. The results reveal an optimum efficiency of the InGaN solar cell of ~ 15.32 % at a band gap value of 1.32 eV. It has been observed that lowering the doping concentration N_A leads to an improvement of the short circuit current density (J_sc) (34 mA/cm² at N_A of 10¹⁶ cm⁻³). This might be attributed to the increase of the carrier mobility and hence an enhancement in the minority carrier diffusion length leading to a better collection efficiency. Additionally, the results show that increasing the front layer thickness of the InGaN leads to an increase in the J_sc and to the conversion efficiency (η). This has been referred to the increase in the photogenerated current, as well as to the less surface recombination rate.

Abstract: Thin film solar cell is the best alternative to replace Si solar cell, which has the advantages of low cost, no pollution and so on. It has been developing rapidly in recent years. CuInTe₂ thin-film battery which is similar to CIS thin-film battery belongs to Cu-A^Ⅲ-B^VI₂ sulfur compounds. The energy gap of CuInTe₂ are about 1.06eV, and it is a kind of good absorbing layer material. In this paper, the research history of the CuInTe₂ thin film materials is briefly introduced. It only stays at the stage of preparation and performance testing, and has not been prepared for the finished battery at present. The feasibility and advantages of CuInTe₂ as photoelectric material are explained from it’s structure characteristics. The advantages and disadvantages of various methods of preparing thin film materials are analyzed and impurities in the process are found in the progress. The optical properties and electrical properties of the CuInTe₂ thin-film cells can be tested without the preparation of a battery due to the complexity of thin film solar cell structure.

Abstract: Si-based photonic crystal device such as solar cells have been developed and attract lots of attention. Whether what kind of different structures are used, two key problems are needed to investigate. One is the improvement of the optic-electric (or electric-optic) transformation efficiency. Another is the capability to modulate the light-emitting and detection wavelength for various industrial applications. The wavelength of the light emission and detection can also be further adjusted by changing the material band-gap. In this work, we develop the periodic nanoscale surface textured solar cells. The characteristics of top thin film textured solar cells is developed and estimated to see if the structure is worthy to be scaled from the modern micrometer (um) level down to the nanometer (nm) level continuously. The process of nm-scale textured Si optoelectronic device used in this work is fully comparable to the modern CMOS industry. Optimal Ge concentration in SiGe-based solar cells has been investigated qualitatively by the systemic experiments. With the appropriate addition of Ge to a SiGe-based solar cell, the short current density (Isc) is successfully increased without affecting the open-circuit voltage (Voc) and then the overall efficiency is successfully improved about 4 % than the nanoscale surface textured Si solar cell.

Abstract: In this paper, SnS2, SnS2:Cu and SnS nanocrystals were prepared by hydrothermal method and the thin film solar cell with the novel structure of FTO/SnS2:Cu/ SnS/Sn was fabricated by dipping-coating technique. The thin film solar cell gave the short circuit photocurrent density of 37.5 μA·cm−2, open circuit voltage of 130 mV, and fill factor of 0.35, corresponding to the photoelectric conversion efficiency of 0.17 %.

Abstract: It is widely accepted that graded buffer layer between the p-layer and i-layer increase the efficiency of amorphous silicon solar cells. The open-circuit voltage (V_oc), short current density (J_sc) and fill factor (FF) of the thin film solar cell are obviously increased. In the present study, hydrogenated amorphous silicon (a-Si:H) thin film solar cells have been fabricated by 27.12 MHz plasma enhanced chemical vapor deposition (PECVD). We discussed the three conditions at the p/i interface without buffer layer, buffer layer and graded buffer layer of thin film solar cells by TCAD software. The influences of the performance of the solar cell with the different buffer layer are investigated. The cell with graded buffer layer has higher efficiency compared with the cells without buffer layer and buffer layer. The graded buffer layer enhances the conversion efficiency of the solar cell by improving V_oc and FF. It could be attributed to a reduction of interface recombination rate near the junction. The best performance of conversion efficiency (η)=8.57% (V_oc=0.81 V, J_sc=15.46 mA/cm², FF=68%) of the amorphous silicon thin film solar cell was achieved.

Abstract: In this investigation the surface properties optimisation of a flexible PEN foil to use as substrate for thin film silicon solar cells is presented. The polymer surface, usually hydrophobic and inactive to chemical reactions, can give poor adhesion for films deposited on it. Furthermore, gas desorption from the polymer sometimes causes serious problems to the quality of the devices. To overcome these problems a thin film of silica-like functional material has been developed on polymer foil. Silica-like films were produced by sol-gel process starting from an organic silanes compound (APTMS) as precursor and the solution was deposited by spin-coating. Amorphous silica-like films were obtained with a hydrophilic surface. They were smooth, dense, homogeneous, transparent and exhibited an excellent adhesion to the polymer substrate due to the chemical bond between amine groups of the APTMS with carbonyl bonds in PEN. Physical properties such as elastic modulus and hardness and the UV irradiation effect on structure and surface hydrophilicity of the silica-like coatings have been analysed. A water contact angle of 34° was obtained after UV irradiation. Nanoindentation analysis showed that the silica-like coating have an hardness and an elastic modulus up to 2.0 GPa and 13.2 GPa respectively much higher than that of pure PEN. Oxygen permeability measured on silica-like coated PEN gave a value of 5.7 x 10-9 cc m/m2 s atm showing larger barrier properties respect to pure PEN. Strong adhesion, improved mechanical properties and barrier effect of our silica-like coating make the modified PEN substrate suitable to be used in thin film solar cell technology.