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.

The Light-Trapping Character of Pit Arrays on the Surface of Solar Cells

“…However, compared with traditional energy resources, solar energy experiences deficiencies such as high manufacturing cost and unideal transform efficiency, which seriously limit its wide application. To improve the conversion efficiency, researchers have developed light-trapping structures for various solar cells, such as nano/micro-pyramids [1][2][3][4], nanowires [5][6][7], nanocone [8][9][10][11][12], nanosphere [13][14][15][16], and porous silicon structures [17,18]. Light-trapping structures possess broadband optical absorption abilities, which can effectively lower the loss of light caused by reflection and raise the valid length of optical paths in the active layer of solar cells [19].…”

A New Texturing Approach of a Polyimide Shielding Cover for Enhanced Light Propagation in Photovoltaic Devices

“…Relatively recent reports found that optimal morphology is neither perfectly ordered nor totally random but a mixture of both categories [19,20]. Among the procedures to fabricate textures, one can mention: hot-embossing method [21], UV nanoimprint lithography [22], nanosphere lithography [23] and other microfabrication routes [24]. Few studies are focused on texturing of the classical glass cover by means of the aforementioned methods for better light management [24][25][26].…”