摘要
报道了p-GaN/Al0.35Ga0.65N/GaN应变量子阱结构的肖特基紫外探测器的制备及性能.器件的测试结果表明,在p-GaN/Al0.35Ga0.65N/GaN双异质结中强烈的压电极化和Stark效应共同作用下使得器件在正偏和反偏时的响应光谱都向短波方向移动了10nm.零偏下器件在280nm时的峰值响应为0·022A/W,在反向偏压为1V时,峰值响应增加到0·19A/W,接近理论值.在正向偏压下器件则呈平带状态,并在283和355nm处分别出现了两个小峰.在考虑极化的情况下,通过器件中载流子浓度分布的变化解释了器件在不同偏压下的响应特性,发现p-GaN/Al0.35Ga0.65N/GaN中的极化效应对器件的响应特性影响很大,通过改变偏压和适当的优化设计可以使探测器在紫外波段进行选择性吸收.
The fabrication and performance of a p-GaN/AIGaN/GaN Schottky photodetector are reported. Due to the polarization and Stark effects,spectral responses with a 10nm blue shift are observed. Under zero bias, the peak responsivity of the device is about 0. 022A/W,and it increases to 0.19A/W under 1V reverse bias. The responsivity of the device is flat under a small forward bias,and two peaks appear at 283 and 355nm when the forward bias is increased to 1V. Based on the measurements and the polarization effect, the changes of carrier distribution are used to explain the working mechanism of this Schottky photodetector. The polarization effects can fundamentally affect the device response characteristics. Optimizing the device design and changing the bias can change the responsivity region and improve the peak responsivity of this Schottky ultraviolet photodetector.
