Simulation of Growth of Silicon Thin Films on Textured and Non-textured Surface: A Comparative Study

Abstract

We analyzed the difference in growth of thin film silicon layers when deposited on a textured and a non-textured surface. In this investigation characteristics of two solar cells were compared, where one cell was prepared on a textured surface (Cell-A) while the other prepared on a non-textured surface (Cell-B). The intrinsic film deposited on a textured surface was found more defective (2.4 × 1017 cm−3) than that deposited on a flat surface (3.2 × 1016 cm−3). Lower effective flux density of SiH3 precursors on the textured surface can be one of the reasons for higher defect density in the film deposited on textured surface. An Improved light coupling can be achieved by using a thinner doped window layer. The optimum thicknesses of active layers (d) were estimated for best power conversion efficiency (PCE) of Cell-A & Cell-B, and found to be 135 nm & 300 nm respectively. As higher optical transmission of a wide band gap p-type doped window layer is one of the primary concerns, we estimated the effect of using thinner p-type layer for improving optical transmission. By changing the thickness from 15 nm to 3 nm, we observed that the short circuit current density (Jsc) increased from 16.4 mA/cm2 to 20.96 mA/cm2 and PCE increased from 9.4% to 12.3%. Furthermore, it was also noticed that all other device parameters also increased in this process.