在异质外延β-Ga2O3单晶薄膜上实现快速响应日盲光电探测器

High-Temporal Dynamic β-Ga2O3 Schottky Type Solar-Blind Photodetector via Heteroepitaxy Single Crystalline Film

摘要:

通过等离子体辅助分子束外延（PA-MBE），在双抛蓝宝石衬底上生长出两英寸的高质量β-Ga₂O₃单晶薄膜。利用光刻技术和电子束蒸镀金叉指电极，在薄膜上成功地制备了金属-半导体-金属结构（M-S-M）型日盲光电探测器。结果表明：日盲光电探测器的暗电流低至130 pA（20 V），对紫外波段的光响应度达到229 mA?W^-1；此外，器件对光信号表现出超快的瞬态特性，衰减时间为1.31 ms，器件的优异性能可归因于β-Ga₂O₃的高结晶质量和肖特基结的巨大场迁移率。该研究为未来基于更大规模的β-Ga₂0₃异质外延薄膜的深紫外（DUV）光电探测器的应用迈出了重要一步。

Abstract:

In this report， we successfully fabricate a β-phase Ga₂O₃ single-crystalline film based high performance solar-blind photodetector. Based on β-Ga₂O₃ single crystalline film hetero-grown via plasma-assisted molecular beam epitaxy （PA-MBE） on sapphire substrates， the solar-blind detector is constructed by interdigitated Au-electrode with the metal-semiconductor-metal structure. The dark-state current of the device is low as 130 pA， meanwhile the UV photon-responsivity is >229 mA?W^-1 at the peak of 225 nm. Moreover， the device exhibits an ultrafast transient characteristic of DUV signals with a decay time of 1.31 ms. The excellent performances of the device could be attributed to the high crystalline quality of β-Ga₂O₃ and giant field mobility in Schottky junction. Our results present a significant step towards future applications of two-dimension array DUV photodetector based on larger scale β-Ga₂O₃ heteroepitaxy film.