A Simulation Study for a-SiGe Solar Cell Using AMPS-1D

• Main Authors: Tien-Yu Liao, 廖天佑
• Other Authors: 張書通
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/6fvgry

碩士 === 國立中興大學 === 電機工程學系所 === 102 === To effectively model the characteristics of solar batteries and its material properties, non-commercial simulation software known as AMPS-1D (developed by the University of Pennsylvania) was employed to construct models of amorphous silicon and hydrogenated amorphous silicon-germanium solar cells. The model of hydrogenated amorphous Si-Ge solar cells, which have an intrinsic layer (I-layer) made fromhydrogenated amorphous Si-Ge, are built by varying the material property parameters, light absorption coefficient, and the structure of basic amorphous silicon solar cells. Experimental results on actual samples prepared by Green Energy and Environment Research Laboratories (GEL) in Industrial Technology Research Institute (ITRI) were used to verify that the proposed model produces the same output characteristics. During the simulation process, the energy gap of hydrogenated amorphous Si-Ge solar cells varied with changes in its inherent properties caused by doping conditions. This further affected its light absorption performance. To simplify this model, an approximate model of light absorption coefficient was adopted and approximation procedures were established in this study. The reliability of the approximation procedures was validated using samples at ITRI. In the future, reflectance (R) and transmittance (T) coefficients will be obtained from experiments and used to derive the optimal absorption coefficient following the same approximation procedures. The characteristics of hydrogenated amorphous Si-Ge intrinsic layer and the characteristic changes of solar cells resulting from a p-n heterojunction are discussed based on the simulation results. The effect of various parameters on output characteristics was observed through varying the doping concentration and film thicknesses of p, I, and n layers. Chapter 1 indicates this study’s research motivation and presents the sunlight spectrum and fundamental characteristics of light. The relationships between transmittance and reflectance coefficients and the absorption coefficient are derived. Chapter 2 introduces components in the solar batteries, including component structure, operating mechanism, property derivation, characteristics of electric current and voltage, simplified equivalent circuit model, and various parameters. Chapter 3 utilizes AMPS-1D to model the actual samples provided by GEL at ITRI. The underlying principle and physical models of the software are introduced first, and then followed by model construction. Chapter 4 presents experimental results and discussion. The output characteristics of single layer amorphous Si and nanocrystalline Si solar cells with different film thicknesses and doping concentrations were observed. To achieve the optimal energy gap structure of multi-junction amorphous solar cells, the conversion efficiency of multi-junction amorphous Si and nanocrystalline Si solar cells was studied by varying film thickness and energy gap of Tunnel Recombination Junction (TRJ) and changing the energy gap of multi-junction amorphous Si and nanocrystalline Si absorption layer. Finally, the conclusions are drawn in Chapter 5.