Analysis of poly-Si thin filmp+-n-n+homojunction solar cell and heterojunction solar cell with and without a thinμc-Si layer at the interface ofa-Si and poly-Si layers

Abstract

In this study, new possibilities for higher efficiency poly-Si thin film solar cells are investigated using MEDICI TM device simulator. The poly-Si p + - n - n + thin film solar cell with a thin a -Si p + layer is found to have higher efficiency than the homojunction p + - n - n + cell. Further improvement in efficiency of the heterojunction p + - n - n + cell is achieved by introducing a thin μ c-Si layer at the interface of a -Si emitter and poly-Si absorber layers. The μ c-Si layer at the interface is found to reduce the recombination losses at the interface and improved the fill factor and efficiency of the cell. The photovoltaic parameters of the cell and the absorber layer thickness for optimum efficiency are highly influenced by grain size and passivation at the grain boundary.