Preparation And Characterization Of ZnO/MgZnO Multiple-quantum Well

Recently, more attention has been paid to ZnO-based semiconductors due to their potential applications in optoelectronic devices in blue and ultraviolet spectra of light. Heterostructures, superlattices and multi-quantum wells (MQW) are used to improve its performance. In the quantum wells, due to the quantum confinement effect, the band gap energy can be adjusted by changing the thickness of the well layers, and the density of exciton and efficiency of photoluminescence can be enhanced.ZnO/ZnMgO multiple-quantum wells (MQWs) with different well width were deposited on sapphire (001) as substrates by using pulsed laser deposition (PLD) method. X-ray diffraction (XRD), photoluminescence spectra (PL) taken at room and low temperatures were used to characterize the structural and optical properties of the MQWs. The XRD results show that the MQWs films have the excellent epitaxial relationship with the substrates. It is found that the crystallinity of the MQWs firm is improved with the decrease of the well width. PL measurement shows that all the MQWs with different well width exhibit high PL quantum efficiency and the observable quantum confinement effect. The maximum blue-shift of ultraviolet peaks is found to about188meV.