Numerical Optimization of 0.5‐μm‐thick Cu (In1-xGax) Se2 Solar Cell

摘要： This paper presents a numerical simulation of 2D ultra-thin Cu (In1-xGax) Se2 solar cell under drift-diffusion transport across heterojunction interfaces. The validation of the CIGS model is performed by matching the electrical characteristics of the experimental and simulation results. The surface recombination velocity of CdS/CIGS heterojunction interface and element composition Ga/(In+Ga) ratio effect on the optical properties and electrical performances of CIGS absorber are investigated. The thickness dependence and carrier concentration of the semiconductor layers on the cell performance are investigated. The nanostructured Ag, Au, or Cu back mirror is used to replace conventional Mo back contact to improve light absorption in the ultra-thin CIGS layer. Best power conversion efficiency of 21.74 % has been obtained with a thinner absorber of about 0.5‐ μm‐ thick under AM1.5 illumination condition, 300K.