GaN基MIS紫外探测器的电学及光电特性

制备了GaN基金属-绝缘层-半导体(MIS)结构紫外探测器,并测量了其暗电流和光谱响应。通过分析其暗电流,发现在反偏情况下,其主要电流输运机制为隧穿复合机制;在正偏情况下,随着偏压的增大,电流输运机制从隧穿机制变为空间电荷限制电流机制。光谱响应测试结果显示,该探测器在-5 V的偏压下,在315 nm处获得了最大响应度170 mA/W,探测度为2.3×10¹² cm·Hz^1/2·W^-1。此外,还研究了不同厚度I层对器件光电压的影响,结果表明,光电压受隧穿机制与漏电流机制的共同制约。

Electrical and Optoelectronics Characteristics of GaN Based MIS Photo-detectors

The GaN based metal-insulator-semiconductor (MIS) ultraviolet (UV) photodetectors were fabricated. The dark I-V curves and responsivity spectrum of the photodetectors were mea-sured, and the current transport mechanisms were analyzed. By analyzing the current transport mechanics, it was found that the tunneling-recombination mechanism dominated at the reverse bias and with the forward bias increasing, the current transport mechanism changed from tunneling mechanism to space charge limited current (SCLC) mechanism. Under 5 V reverse bias, it was found that the best responsivity and detectivity of the GaN based MIS detector were 170 mA/W and 2.3×1012 cm·Hz1/2·W-1 at 315 nm. The photo-voltages of GaN based UV photodetectors of different depth of insulator layers were studied, and it was found that the photo-voltage was limited by the tunneling procedure and leakage current.