Highly transparent Zn1−xMgxO/ITO multilayer for window of thin film solar cells

Abstract

Texture-etched Zn1−xMgxO films were fabricated and applied as front transparent electrodes for superstrate type thin film solar cells. The Zn0.65Mg0.35O film (x = 0.35) showed optical transparency better than commercially available Asahi VU and double-textured ZnO (WT-ZnO) substrates. To provide pertinent conductivity, ITO film was coated on the texture-etched Zn0.65Mg0.35O. By employing the Zn0.65Mg0.35O/ITO substrate instead of the SnO2, we demonstrated an enhancement of quantum efficiency for amorphous silicon thin film solar cell devices, resulted in efficiency improvement from 8.92 to 9.56%. We also examined effectiveness of the Zn0.65Mg0.35O/ITO substrate for the microcrystalline silicon solar cells which delivered an efficiency of 9.73% with proper anti-reflection coating. Our experimental results suggest that the Zn0.65Mg0.35O/ITO multilayer front contact can be beneficial for reinforcing performances of silicon-based thin film solar cell devices.