Study of the light-trapping effects of textured ZnO:Al/glass structure TCO for improving photocurrent of a-Si:H solar cells

Effects of using ZnO:Al (AZO) transparent conducting oxide films on the performance of the hydrogenated amorphous Si (a-Si:H) solar cells are studied. AZO films are prepared by the sol-gel method. Rapid thermal annealing (RTA) in vacuum of these films results in a decrease in resistivity. AZO films exhibit a high transmittance in the visible region and excellent resistance against hydrogen radical exposure. The light-trapping effect is proven by a measured decrease in the transmittance and reflectance spectra of the textured AZO/glass structure with a RMS roughness of 67.5 nm. It is concluded that highly textured AZO/glass structures enhance the photocurrent in a-Si:H-based thin film solar cells.