热氧化法制备ZnO薄膜及其紫外探测特性研究

Ultraviolet Photodetection of ZnO Films by Oxidation of Zn Films

采用电子束蒸发方法在玻璃衬底上沉积了Zn薄膜，然后在空气中进行了400℃至550℃加热退火处理，并基于金属-半导体-金属（MSM）平面式结构，制备了ZnO光电导型紫外探测器。实验发现：退火后的薄膜样品表面出现了ZnO纳米线，纵横比在300-1000间；探测器的响应峰值波长约为360nm，紫外区光响应度是可见区的5倍以上；360nm紫外光照射的瞬态响应符合e指数变化规律，e指数曲线拟合所得到的驰豫时间常数反映了这个过程中的时间积累。

Zn films were deposited on glass substrates by electron beam evaporation,and then were annealed from 400℃to 550 ℃ in air. ZnO photoconductive ultraviolet detectors were fabricated based on metal-semiconductor-metal planar structures. After thermal oxidation,ZnO films covered with ZnO nanowires were grown. The aspect ratio of ZnO nanowires varies from 300 to 1000. The photoresponsivity of detectors in the ultraviolet range is about 5 times than that in the visible range, and the peak values are arund 360 nm The photoconduetivity transients are performed with the illuminated light of 360 nm. The response curve of the detector is fitted well with the exponential curve,and the relaxation time constant obtained from the curve fitting represents the time accumulation during the process.