近年来，可见盲与太阳盲光电探测器在火灾监控、太空通信和导弹尾焰探测等方面的应用引起了越来越多的关注。由于氮化镓(GaN)是直接宽带隙半导体材料，所以成为了在可见区与紫外区的光电器件的首选材料，而p-i-n结构的器件因其响应度高、暗电流低、便于集成等优点倍受人们的青睐。采用金属有机气相外延(MOCVD)法制备了p-i-n结构的GaN紫外光电探测器。在此基础上，采用N2气氛下热退火处理的方法，提高了p型GaN层的载流子浓度，从而降低了器件的暗电流。器件在1 V偏压下，暗电流仅为65 pA。器件在1 V偏压下的最大响应度值出现在361 nm处，大小为0.92 A/W。

Great attention has been received in recent years for the applications of visible-blind and solar-blind photodetectors, such as flame sensing, secure space-to-space communications, and missile plume detection. Due to the direct wide band gap, GaN is an excellent choice for optoelectronic devices in the visible and the ultraviolet (UV) portion of the spectrum. The p-i-n structure is an attractive candidate for an UV photodetector because of its high responsivity, low dark current and the facility in integration. The p-i-n structured GaN photodetectors have been fabricated on sapphire substrates by metalorganic chemical vapor deposition (MOCVD) in this paper. Furthermore, the carrier density of p-type GaN layer can be enhanced by thermal treatment in N2 ambience, which results in reducing dark current. The dark current of the device is only about 65 pA at 1 V bias. The maximum responsivity of the device is 0.92 A/W at 361 nm under 1 V bias.