Low-temperature solution growth of textured zinc oxide films for light trapping enhancement in thin film silicon solar cells

Abstract

We study the pyramid-like textured zinc oxide films from low-temperature chemical bath deposition as a promising light trapping component in thin film silicon solar cells. It is found that the surface texture increases as the film thickness increases, while the preferential orientation of the crystal also changes gradually during the film growth. The textured zinc oxide film exhibits high transparency over 80% even for a relatively thick (e.g., 3.5 μm) film. Numerical modeling further indicates that the short circuit current of the thin film microcrystalline silicon solar cell can be increased by 20% due to the light trapping effect arising from the textured zinc oxide film. Meanwhile, the sheet resistance of the as-grown textured zinc oxide film can be reduced drastically by hydrogen plasma treatment.