MgO(100) template layer for CdO thin film growth: Strategies to enhance microstructural crystallinity and charge carrier mobility

A simple strategy of using thin, highly (100)-oriented MgO films as template layers for CdO thin film growth by metal-organic chemical vapor deposition on amorphous glass substrates is presented. For comparison, CdO films are grown simultaneously on clean glass, on a 50 nm MgO(100) template layer on glass, and on single-crystal MgO(100). X-ray diffraction as well as four-probe conductivity and Hall-effect measurements reveal that the 50 nm MgO(100) template layer significantly improves the microstructural texture and charge carrier mobility of the overlying CdO thin films. Thus, highly textured CdO thin films with an x-ray diffraction rocking curve full width at half maximum of 2.1° and large carrier mobilities of 160 cm2 V s can be achieved on amorphous glass. Substrate effects, film microstructures, optical properties, and surface morphologies of the CdO films on the different substrates are discussed.