Numerical simulation and optimization of Si/BaSi 2 heterojunction and BaSi 2 homojunction solar cells

Abstract High light absorption material BaSi 2 based heterojunction and homojunctin solar cells were simulated with the program AMPS (analysis of microelectronic and photonic structures)-1D in order to thoroughly understand the mechanism for further improvement in conversion efficiency. Simulation results demonstrated that p + -Si/n-BaSi 2 heterojunction solar cells exhibited superior photoelectric performances as compared with n + -Si/p-BaSi 2 solar cells. A high conversion efficiency up to of 22.7% were achieved by p + -Si (100 nm, N A   =  5  ×  10 19 cm −3 )/n-BaSi 2 (2000 nm, N D   =  1  ×  10 18 cm −3 ) heterojunction solar cell. For BaSi 2 /BaSi 2 homojunction solar cells, the window layer should be designed as thin with large scale uniformity and high quality in achieving high efficiency. Both n + -BaSi 2 (5 nm, N D   =  5  ×  10 19 cm −3 )/p-BaSi 2 (2000 nm, N A   =  1  ×  10 17 cm −3 ) homojunction and p + -BaSi 2 (5 nm, N A   =  5  ×  10 19 cm −3 )/n-BaSi 2 (2000 nm, N D   =  1  ×  10 17 cm −3 ) homojunction solar cells gave out a high conversion efficiency of 22.5%. Both donor-like defects in p-BaSi 2 and acceptor like defects in n-BaSi 2 light absorption layers were identified to significantly influence the solar cell performance that all parameters deteriorated severely under high bulk defect density. Moreover, p + -Si/n-BaSi 2 solar cell was more sensitive to high level interface trap defects on account of the sharp dropping down of Eff under high interface trap density over 5  ×  10 12 cm −2 . This work provided insight essential guidance for device design and optimization in achieving high efficiency silicide solar cell with low cost.