ZnMgAlO based transparent conducting oxides with modulatable bandgap

ZnMgAlO films with a broad spectral range of optical transmission and high conductivity were prepared by pulsed laser deposition. The optical and electrical properties of ZnMgAlO films could be controlled by adjusting Al and Mg contents. As the Mg content increased from 10 to 30 at.%, the bandgap value could be modulated from 3.78 to 4.66 eV, and the transparent wavelength range was widened within near-UV, visible and near-IR regions. The optimized ZnMgAlO film possesses a wide bandgap of 4.5 eV and a low resistivity of 1.6×10−3Ω cm. The broad spectral range of optical transmission and high conductivity maked ZnMgAlO films are of interest as TCO window materials for optoelectronic devices.

Research highlights
► ZnMgAlO films provide a new way of bandgap modulation for TCOs.
► High conductivity can be achieved by optimizing the Al content.
► The energy bandgap mainly depends on the Mg content.