Quasi-hemispherical pit array textured surface for increasing the efficiency of thin-film solar cells

Abstract

Enhancing light absorption is an important way for solar cells to increase the conversion efficiency. In this paper, we prepared a quasi-hemispherical pit array texture on the glass surface through the micro-fabrication process. Then, silicon thin-film (a-Si:H) solar cells were deposited on the other smooth surface. Pit array textured cells exhibit a higher short-circuit current density and power conversion efficiency than flat devices by ∼7% and 5%, respectively. The reflectance spectrum of textured solar cells is considerably reduced, and the external quantum efficiency is considerably improved in the 300–800 nm wavelength range. Through COMSOL Multiphysics and finite-difference time-domain (FDTD) simulation, three significant effects identify light-trapping characteristics for textured structures: surface reflection reduction, secondary absorption, and light scattering. As a result, the textured surface of the quasi-hemispherical pit array can considerably increase the efficiency of solar cells. Meanwhile, the Lumerical DEVICE software was used to simulate the electrical characteristics of the cell, and the experimental results were theoretically proven.