采用反应射频磁控溅射方法,在Si(001)基片上制备了具有高c轴择优取向的ZnO/MgO多量子阱.利用X射线反射、X射线衍射、电子探针,光致荧光光谱等表征技术,研究了ZnO/MgO多量子阱的结构、成份和光致荧光特性.研究结果表明,多量子阱的调制周期在1.85—22.3nm之间,所制备的多量子阱具有量子限域效应,导致了室温光致荧光峰的蓝移,并观测到了量子隧穿效应引起的荧光效率下降.建立了基于多声子辅助激子复合跃迁理论的室温光致荧光光谱优化拟合方法,通过室温光致荧光光谱拟合发现,ZnO/MgO比ZnO/ZnMgO多量子阱具有更大的峰位蓝移,探讨了导致光致荧光光谱展宽的可能因素.
Wurtzite ZnO/MgO superlattices were successfully grown on Si(001 ) substrates at 750% using radio-frequency reactive magnetron sputtering method. X-ray reflection and diffraction, electronic probe and photoluminescence analysis were used to characterize the multiple quantum wells (MQWs). The results showed the periodic layer thickness of the MQWs to be 1.85 to 22.3 nm. The blueshift induced by quantum confinement was observed. Least square fitting method was used to deduce the zero phonon energy of the exciton from the room-temperature photoluminescence. It was found that the MgO barrier layers has a much larger offset than ZnMgO. The fluctuation of periodic layer thickness of the MQWs was suggested to be a possible reason causing the photoluminescence spectrum broadening.