MOCVD-grown textured surface ZnO transparent conductive layers with modulated structure for thin film solar cells

• Modulated textured surface ZnO films were obtained by MOCVD.
• Gradient B-doping and sandwich structure exhibited strong scattering capability.
• Sandwich structure exhibits relatively higher electron mobility.
• Modulated textured surface ZnO films are promising TCO materials.

Textured surface zinc oxide (ZnO) transparent conductive oxide (TCO) films with modulated structure have been fabricated using metal organic chemical vapor deposition (MOCVD) on superwhite glass substrates. It was found that gradient boron-doping growth for ZnO films can improve the pyramid-like grain sizes with strong light-scattering capability and optical transparences in near infrared (NIR) region resulting from decreased carrier concentration absorption. Furthermore, ZnO-TCO film with sandwich structure (boron-doped ZnO (ZnO:B)/un-doped ZnO/boron-doped ZnO (ZnO:B)) exhibited relatively higher electron mobility and higher optical transmittances as well as haze values in the wavelength range of 750–1800 nm than the conventional ZnO:B sample.