Optimization of Electrical and Optical Losses in Thin c-Si Bifacial PERC Solar Cells to Module Level Through Modeling

Abstract

The cost of bifacial monocrystalline silicon passivated emitter and rear contact solar cells at the module level can be decreased by optimizing the wafer size. This research work has studied electrical and optical loss analysis for 180–90 µm wafer sizes. The solution of thinned 90 µm PERC solar cells to the module level, its performance, and comparison to the reference (180 µm) and undesigned (90 µm) PERC cells have been addressed through SunSolve simulations. A 72-cell bifacial c-Si PERC solar module was simulated with an optimized wafer thickness of 90 µm. The cell performance at a longer wavelength was improved by depositing Al₂O₃/SiN_x/SiO_x films on the rear of PERC solar cells. SiO_x, SiN_x, SiN_y, and SiO₂ films were deposited on the front side of the PERC solar cell to improve light absorption at shorter wavelengths. The present simulation design with optimized performance led to an average increase of open circuit voltage of 24.7 mV from 699.3 mV to 724 mV, an average increase of fill factor of 0.89% from 79.06% to 79.95%, and an average increase of packing conversion efficiency of 0.96% from 21.78% to 22.74%, as compared to the designed (90 µm) and reference (180 µm) cells. The simulation results showed that the designed cell absolute efficiency has improved compared to the reference cell. The optimized PERC solar cell and its parameters simulated a 72-cell bifacial solar module. The module showed average values of 51.75 V, 9.181 A, 384.3 W, 80.9% and 19.72% for V_oc, I_sc, P_mp, FF and efficiency. The bifaciality factor of the present module was 78.4% under standard test conditions (STC).