ZnMgBeO/Ag/ZnMgBeO transparent multilayer films with UV energy bandgap and very low resistance

The ZnMgBeO/Ag/ZnMgBeO multilayer structures were sputter grown and their electrical and optical properties have been investigated in detail. Results indicated that the ZnMgBeO(30 nm)/Ag(10 nm)/ZnMgBeO(30 nm) optimum structure shows energy bandgap of ~4.5 eV, electrical resistivity of ~6.5×10−5 Ωcm, and optical transmittance of 78-90% over the visible wavelength range and 74-90% over 300-400 nm range, representing a significant improvement over the previously reported transparent conducting films. High resistivity (~0.12 MΩcm) of the ZnMgBeO layer did not critically affect the conductivity of the multilayer, because the Ag films act as the conducting path. It was also observed that the properties were substantially deteriorated at the Ag thickness of 5 nm, as the Ag film is only partly continuous, resulting in very rough interfaces and surfaces.