基于Pt电极的TiO2紫外探测器研究

针对宽禁带半导体紫外探测器响应不够灵敏和响应度偏低等问题,将具有高功函数的Pt电极引入TiO2紫外探测器,采用溶胶凝胶法制备了纳米TiO2薄膜。以金属Pt为电极,采用磁控溅射的方法,将Pt电极溅射在TiO2纳米薄膜上,制作了MSM（Metal-Semiconductor-Metal）型紫外探测器件。在5 V偏压下,探测器的暗电流为4.5 nA,260 nm波长光照下的光电流为5.7μA。在260 nm的紫外光照射下,探测器的响应度达到最大值,约为447 A/W,与其他紫外探测器（200 A/W左右）的响应度均值相比有了很大的提升。最后,设计外围电路,制作出功能完整的紫外强度测试仪。实验表明,该探测器成功地解决了传统宽禁带半导体紫外探测器灵敏度及响应度偏低等问题。

Research on TiO2 Ultraviolet Photodetectors with Pt Electrodes

To solve the problems of insensitive response and low degree photoresponse in wide bandgap semiconductor UV（ultraviolet） photodetectors,Pt electrodes with high work function was introduced to TiO2 ultraviolet detectors.TiO2 ultraviolet detectors with Pt electrodes have been fabricated and studied.Nano TiO2 thin films were prepared by sol-gel method,and Pt film was deposited by radio frequency magnetron sputtering directly on the semiconductor films.At 5 V bias,the dark current of the detectors was 4.5 nA,and the photocurrent was 5.7 μA under irradiation of 260 nm UV light.High photoresponse of 447 A/W was found under irradiation of 260 nm UV light,which is much higher than those of photodetectors with other electrodes（about 200 A/W）.At last,the peripheral circuit was designed and the final UV photodetector was fabricated.Experiments show that the detector successfully solve the problems of traditional wide-bandgap semiconductor ultraviolet detector.