Wang Yuefei, Fu Shihao, Han Yurui, Gao Chong, Fu Rongpeng, Wu Zhe, Cui Weizhe, Li Bingsheng, Shen Aidong, Liu Yichun
Key Laboratory of UV Light Emitting Materials and Technology, Ministry of Education, Northeast Normal University, Changchun, 130024, China.
Department of Electrical Engineering, The City College of New York, New York, 10031, USA.
Small. 2025 Feb;21(8):e2406989. doi: 10.1002/smll.202406989. Epub 2025 Jan 15.
In this study an (AlGa)O barrier layer is inserted between β-GaO and GaN in a p-GaN/n-GaO diode photodetector, causing the dark current to decrease considerably, and device performance to improve significantly. The β-GaO/β-(AlGa)O/GaN n-type/Barrier/p-type photodetector achieves a photocurrent gain of 1246, responsivity of 237 A W, and specific detectivity of 5.23 × 10 cm Hz W under a bias of -20 V. With the irradiation of 250 nm solar-blind ultraviolet light, the photocurrent exhibits a dramatic nonlinear increase beyond a bias of ≈-4 V, attributed to interband electron tunneling. The onset of interband tunneling at a relatively low bias is due to the strong internal electric field formed by self-trapped holes (STHs) in GaO. This study also proposes an effective way to suppress persistent photoconductivity and significantly increase the device operation speed in photodetectors fabricated from GaO through the light-induced neutralization of STHs.
在本研究中，在p-GaN/n-GaO二极管光电探测器的β-GaO和GaN之间插入了一层(AlGa)O势垒层，使得暗电流大幅降低，器件性能显著提高。β-GaO/β-(AlGa)O/GaN n型/势垒/p型光电探测器在-20 V偏压下实现了1246的光电流增益、237 A/W的响应度以及5.23×10 cm Hz W的比探测率。在250 nm日盲紫外光照射下，当偏压超过≈-4 V时，光电流呈现出急剧的非线性增加，这归因于带间电子隧穿。在相对较低偏压下发生带间隧穿是由于GaO中自陷空穴（STH）形成的强内部电场。本研究还提出了一种有效的方法来抑制持续光电导，并通过光致中和STH显著提高由GaO制造的光电探测器中的器件运行速度。
