Enhanced Conversion Efficiency of a-Si:H Thin-Film Solar Cell Using ZnO Nanorods

Abstract

The surface reflectivity of a material will vary as light passes through interfaces with different refractive indices. Therefore, the optical loss and reflection of an optical-electronic component can be reduced by fabricating nanostructures on its surface. In the case of a solar cell, the presence of nanostructures can deliver many different advantages, such as decreasing the surface reflectivity, enhancing the light trapping, and increasing the efficiency of the carrier collection by providing a shorter diffusion distance for the photogenerated minority carriers. In this study, an approximately 50-nm thick seed layer was first prepared using spin coating. Zinc oxide nanorods (ZnO-NRs) were then grown using a chemical solution method (CSM). The ZnO-NRs were approximately 2 μm in height and 100 nm in diameter. After applying them to amorphous silicon (a-Si:H) solar cells, the short-circuit current density increased from 8.03 to 9.24 mA/cm2, and the photovoltaic conversion efficiency increased by 11.24%.