New natively textured surface Al-doped ZnO-TCOs for thin film solar cells via magnetron sputtering

Natively textured surface aluminum doped zinc oxide (ZnO:Al) thin films were directly deposited via pulsed direct current (DC) reactive magnetron sputtering on glass substrates. During the reactive sputtering process, the oxygen gas flow rate was varied from 8.5 sccm to 11.0 sccm. The influences of oxygen flow rate on the structural, electrical and optical properties of naturally textured ZnO:Al TCO thin films with milky surface were investigated in detail. Gradual oxygen growth (GOG) technique was developed in the reactive sputtering process for textured ZnO:Al thin films. The light-scattering ability and optical transmittance of the natively textured ZnO:Al TCO thin films can be improved through gradual oxygen growth method 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%).

Graphical abstractThe light-scattering ability and optical transmittance of the natively textured surface ZnO:Al TCO thin films can be improved through gradual oxygen growth method while maintaining a low sheet resistance.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Natively textured surface ZnO:Al thin films have been deposited via magnetron sputtering on glass substrates. ► Oxygen flow rates have significant influences on the thin film properties. ► Typical textured surface ZnO:Al thin films exhibit crater-like surface morphology. ► Light-scattering ability and optical transmittance can be improved through gradual oxygen growth method. ► They are promising transparent conductive oxide layers for thin film solar cells.