Fabrication and electroluminescence of sheet-like ZnO/Si light-emitting diodes by radio frequency magnetron sputtering method

Abstract

Sheet-like ZnO/Si light emitting diodes (LEDs) have been fabricated through depositing nanoscale ZnO on the p-type single crystal silicon by using a radio frequency (RF) magnetron sputtering method. From XRD patterns, the (1 0 0), (0 0 2) and (1 0 1) diffraction peaks can be observed. Through increasing the sputtering time, however, the intensity of (1 0 0) and (1 0 1) diffraction peaks has gradually decreased and the intensity of (0 0 2) diffraction peak has gradually enhanced. With decreasing the sputtering powers, the fabricated ZnO films have been observed to show better (0 0 2)-orientation growth. Electroluminescence (EL) from ZnO/Si LEDs have been decomposed into three emission bands, i.e., UV, green and orange emissions, which origin from the band gap, zinc interstitial or vacancies oxygen and shallow level, respectively. Under the lower sputtering power, orange emission is disappeared. It is indicated that the structures and EL properties are sensitive to the fabrication conditions. It is important to optimize and tune the fabrication conditions for purposeful applications in the future works.