modeling of novel structures of amorphous crystalline hetero junction solar cells

• DOI: 10.4229/26theupvsec2011-2bv.2.24
• Publication Date: 2011-01-01
• Authors: S.-Y. Chen; Chao Cheng Lin; C.-L. Chen; J.-C. Hsiao; W.-H. Lu; D.-C. Wu; C.-H. Chen
• Keywords: Wafer-based Silicon Solar Cells and Materials Technology; 7. Clean energy; Silicon Solar Cell Characterisation and Modelling

Hetero-junction with intrinsic amorphous thin-film (HIT) solar cells has been confirmed to achieve 23% by Sanyo Electric. From the theoretical viewpoint, how to further enhance the efficiencies of the silicon solar cells for the next generation is a most critical issue. We are the first to propose the novel solar cell structure of amorphous/crystal heterojunction with front- and back-doping into silicon substrate in order to resolve the carriers transport between heter-jounction. We simulated with various boron doping profiles into front-side silicon wafers based on new proposed structures. The doping densities of both p- and n-a-Si were kept at 1019 cm-3 in this simulation. With higher boron density, Voc and Jsc only slightly vary but F.F. increase more. Therefore, the efficiency can increase due to reduce recombination over interfaces. The insertion of doping profile into silicon really improve the hole carrier transport problems on i-a-Si/c-Si interface. The efficiency can increase due to reduce recombination over interfaces. We further investigated how the rear-side doping density inside silicon affected the efficiencies of HIT solar cells. We don’t observe the enhancement of efficiencies in HIT with phosphorous junction-depth. We speculated the results reflected advantages of i-a-Si/c-Si interfaces. Very few interface states demonstrated great reaction with dangling bonds after i-a-Si deposition on c-Si. The conduction-band differences at i-a-Si/c-Si don’t play an important role limiting the electron carrier transport. Therefore, we don’t need any BSF layer if the great properties i-a-Si can be deposited on c-Si. We expect experiments of delicate shallow doping profile may be achieved by thermal diffusion, or plasma doping or ion-implanting techniques in the future.<br/>26th European Photovoltaic Solar Energy Conference and Exhibition; 1474-1477<br/>