Realization of n-ZnO:Ga / p-ZnO:GaP homojunction by RF magnetron sputtering

ZnO based LEDs are received great attention as it has wide band gap (~3.36 eV) and large exciton binding energy (~60 meV) at room temperature [1]. It is known that the basic components for LEDs are high quality p-type and n-type layers. The undoped ZnO exhibits intrinsic n-type conductivity and doping with III group elements such as B, In, Al, and Ga will enhance the electrical properties. But, it is too difficult to produce high quality p-type ZnO layers due to compensation of native defects, formation of deep acceptor and low solubility of dopants.