Optical and electrical properties of bandgap engineered gallium-doped MgxZn1−xO films

In this study, the optical and electrical properties of heavily gallium-doped MgxZn1−xO films were investigated. Films were epitaxially grown on cc-plane sapphire substrates using pulsed laser deposition. Film transparency was shown to be greater than 90% in the visible spectrum. Absorption was shown to be extended to lower wavelengths in films with higher magnesium concentration values. Although transparency in the ultraviolet wavelength range was improved, conductivity was decreased. In MgxZn1−xO films with 0.5 at.% gallium, resistivity was increased from 1.9×10−3Ωcm to 3.62×10−2Ωcm as the magnesium concentration was increased from five atomic percent to fifteen atomic percent. These efforts will facilitate the development of zinc oxide-based ultraviolet–blue light emitting diodes, ultraviolet–blue light laser diodes, and other optoelectronic devices.