Natively textured surface Al-doped ZnO-TCO layers with gradual oxygen growth for thin film solar cells via magnetron sputtering

Natively textured surface aluminum doped zinc oxide (ZnO:Al) transparent conductive oxide (TCO) thin films have been directly deposited via pulsed direct current magnetron reactive sputtering on glass substrates. Gradual oxygen growth (GOG) techniques were developed in the reactive sputtering process for textured ZnO:Al thin films in reactive magnetron sputtering. The light-scattering ability and optical transmittance of the natively textured ZnO:Al TCO thin films can be improved through gradual oxygen growth methods while maintaining a low sheet resistance. Typical natively textured ZnO:Al TCO thin film with crater-like surface exhibits low sheet resistance (Rs ∼ 4 Ω), high transmittance (Ta > 85%) in visible optical region and high haze value (12.1%). The natively ZnO:Al thin films are promising TCO materials for thin film solar cells.