Comparison of using p-nc-SiOx:H and p-nc-Si:H as window layer in amorphous silicon based solar cells

Abstract

One of the most influencing parameters on the performance of amorphous silicon (a-Si:H) based solar cells is the window layer material. In this way, different kinds of p layers have been studied and investigated for using as window and buffer layers in a-Si:H based devices. The main purpose of this work is to compare the effect of two different p layers, one based on nanocrystalline silicon (nc-Si:H) and the other based on nanocrystalline silicon oxide (nc-SiOx:H), when that using as window layer in two p-p-i-n single junction a-Si:H based solar cells.The behavior of our two structures was simulated by using AMPS-1D, a one- dimensional simulation program for solar cells. Under A.M 1.5 illumination, our calculations results reveal that the structure with p-nc-SiOx:H type window layer shows a higher electrical performances with a value of the efficiency (η) equal to 8.28 %, compared to the cell with p- nc-Si:H window layer (η = 7.83 %). Moreover, a better quantum efficiency (QE) in the short wavelength range for the first structure is due to the higher band-gap and the transparency of the p nc-SiOx:H window layer. Finally, the comaparison of our simulation results with other experimental results was realized and a vigorous agreement was obtained.