Electrically pumped simultaneous ultraviolet and visible random laser actions from ZnO-CdO interdiffused film

Abstract

We have demonstrated electrically pumped simultaneous ultraviolet (UV) and visible random laser (RL) actions from ZnO-CdO interdiffused film. The interdiffusion between ZnO and CdO films at 700 °C forms composition-graded CdxZn1−xO alloy within the ZnO-CdO interdiffused film, which is luminescent in both UV and visible regions. A device based on SiO2/ZnO-CdO/SiO2 double-barrier structure on silicon substrate, where SiO2 acts as the barrier, is constructed for electrical pumping of the ZnO-CdO interdiffused film. As the device is applied with sufficiently high forward bias with negative voltage connecting to the silicon substrate, the UV and visible RL actions simultaneously occur. The mechanism for such electrically pumped RL actions has been tentatively elucidated.