Analysis of the influence of buffer layer on p-a-Si/n-c-Si heterojunction solar cells

The influence mechanism of buffer layer on HIT solar cells is researched by AFORS-HET and MATLAB. First, P layer’s condition is optimized, result shows that high doping, thin thickness P layer should be chosen. Buffer layer have a twofold effect, the influence on density of interface state, and the energy band offsets between with crystalline silicon. Through calculation and simulation with AFORS-HET and MATLAB, it is found that when the density of interface state increases, the density of recombination center would increase, then open circuit voltage decreases. When the band mismatch increases, the interface minority carrier concentration would decline, open circuit voltage then improves. The influence of buffer layer on short circuit current and fill factor is small, but P layer’s condition has a relative bigger influence on them.