Solar-Blind Photodetector with High Avalanche Gains and Bias-Tunable Detecting Functionality Based on Metastable Phase α-Ga2O3/ZnO Isotype Heterostructures
Solar-Blind Photodetector with High Avalanche Gains and Bias-Tunable Detecting Functionality Based on Metastable Phase α-Ga2O3/ZnO Isotype Heterostructures
复制标题
DOI：
10.1021/acsami.7b09812
复制
发表时间：
2017-10-25
影响因子：
9.5
通讯作者：
Ye, Jiandong
中科院分区：
文献类型：
--
作者：
Chen, Xuanhu;Xu, Yang;Ye, Jiandong
亚稳态α相Ga 2 O3是一种新兴的材料，可用于开发面向民用和军事应用的日盲光电探测器和电力电子器件。尽管其上级物理性质，亚稳相α-Ga 2 O 3的高质量外延仍然具有挑战性。为此，首次在非极性ZnO（11（2）over bar 0）衬底上获得了单晶α-Ga 2 O 3外延层，并成功研制出高性能的Au/α-Ga 2 O 3/ ZnO异质结肖特基势垒雪崩二极管。该器件具有自供电功能，暗电流小于1 pA，紫外/可见光抑制比为10（3），探测率为9.66 × 10（1/2）cm Hz（1/2）W-1。截止波长为255和375 nm的双响应带在-5 V时的峰值响应率分别为0.50和0.071 A W-1。低偏压下的高光电导增益是由Au/Ga 2 O 3和Ga 2 O 3/ZnO异质界面处的势垒降低效应决定的。该器件还允许在不同的照明条件下由纯电子和空穴注入引发的雪崩倍增过程。雪崩增益大于103，电子和空穴的电离系数比较低，总增益大于105，响应度为1.10 × 10（4）A W-1。这种雪崩异质结的可调增益和偏压可调的紫外检测功能，为开发高性能的日盲光电探测器的承诺。
The metastable alpha-phase Ga2O3 is an emerging material for developing solar-blind photodetectors and power electronic devices toward civil and military applications. Despite its superior physical properties, the high quality epitaxy of metastable phase alpha-Ga2O3 remains challenging. To this end, single crystalline alpha-Ga2O3 epilayers are achieved on nonpolar ZnO (11 (2) over bar0) substrates for the first time and a high performance Au/alpha-Ga2O3/ ZnO isotype heterostructure-based Schottky barrier avalanche diode is demonstrated. The device exhibits self-powered functions with a dark current lower than 1 pA, a UV/visible rejection ratio of 10(3) and a detectivity of 9.66 X 10(12) cm Hz(1/2) W-1. Dual responsivity bands with cutoff wavelengths at 255 and 375 nm are observed with their peak responsivities of 0.50 and 0.071 A W-1 at -5 V, respectively. High photoconductive gain at low bias is governed by a barrier lowing effect at the Au/Ga2O3 and Ga2O3/ZnO heterointerfaces. The device also allows avalanche multiplication processes initiated by pure electron and hole injections under different illumination conditions. High avalanche gains over 103 and a low ionization coefficient ratio of electrons and holes are yielded, leading to a total gain over 105 and a high responsivity of 1.10 x 10(4) A W-1. Such avalanche heterostructures with ultrahigh gains and bias-tunable UV detecting functionality hold promise for developing high performance solar-blind photodetectors.