Simulation and analysis of Si/PEDOT:PSS hybrid interdigitated back contact solar cell

摘要

Interdigitated back contact (IBC) cells show higher conversion efficiencies as compared to conventional homojunction c-Si solar cells, because the optical shadowing loss by front-side metal fingers and bus bars is completely eliminated. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) is a highly conductive polymer. The Si/PEDOT:PSS hybrid solar cell with interdigitated back contact (IBC) structure combined the solution-based processing advantage of an organic polymer has better performance and lower cost compared with other Si IBC solar cells. In this paper, The influence of PEDOT:PSS layer thickness, PEDOT:PSS conductivity and the interface recombination velocity between silicon and PEDOT:PSS layer on the photovoltaic performance of Si/PEDOT:PSS hybrid IBC solar cell are investigated by two-dimensional simulation software Silvaco TCAD Atlas. The simulation results indicate that the short circuit current, open circuit voltage, fill factor and conversion efficiency with the increase of the PEDOT:PSS layer thickness have a very small increase. it is inferred that PEDOT:PSS layer thickness has a wider process window. In addition, the PEDOT:PSS conductivity over 800 S/cm is advantageous for obtaining a higher conversion efficiency. And the interface recombination velocity between silicon and PEDOT:PSS layer should be less than 1000 cm/s. With the optimum unit design of Si/PEDOT:PSS hybrid IBC solar cell, an enhanced conversion efficiency 21.56% is demonstrated by the simulation under the given simulation conditions.