Xiao Yan, Liu Lin, Ma Zhi-Hao, Meng Bo, Qin Su-Jie, Pan Ge-Bo
Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123, China.
Nanomaterials (Basel). 2019 Aug 26;9(9):1198. doi: 10.3390/nano9091198.
Gallium nitride (GaN) is a superior candidate material for fabricating ultraviolet (UV) photodetectors (PDs) by taking advantage of its attractive wide bandgap (3.4 eV) and stable chemical and physical properties. However, the performance of available GaN-based UV PDs (e.g., in terms of detectivity and sensitivity) still require improvement. Fabricating nanoporous GaN (porous-GaN) structures and constructing organic/inorganic hybrids are two effective ways to improve the performance of PDs. In this study, a novel self-powered UV PD was developed by using -type cobalt phthalocyanine (CoPc) and -type porous-GaN (CoPc/porous-GaN) to construct a vertical heterojunction via a thermal vapor deposition method. Under 365 nm 0.009 mWcm light illumination, our device showed a photoresponsivity of 588 mA/W, a detectivity of 4.8 × 10 Jones, and a linear dynamic range of 79.5 dB, which are better than CoPc- and flat-GaN (CoPc/flat-GaN)-based PDs. The high performance was mainly attributed to the built-in electric field (BEF) generated at the interface of the CoPc film and the nanoporous-GaN, as well as the nanoporous structure of GaN, which allows for a higher absorptivity of light. Furthermore, the device showed excellent stability, as its photoelectrical property and on/off switching behavior remained the same, even after 3 months.
氮化镓（GaN）凭借其具有吸引力的宽带隙（3.4电子伏特）以及稳定的化学和物理性质，是制造紫外（UV）光电探测器（PD）的优质候选材料。然而，现有的基于GaN的紫外光电探测器的性能（例如在探测率和灵敏度方面）仍有待提高。制造纳米多孔GaN（多孔GaN）结构和构建有机/无机杂化物是提高光电探测器性能的两种有效方法。在本研究中，通过使用α型钴酞菁（CoPc）和β型多孔GaN（CoPc/多孔GaN），采用热蒸发沉积法构建垂直异质结，开发了一种新型自供电紫外光电探测器。在365纳米、0.009毫瓦/平方厘米的光照下，我们的器件表现出588毫安/瓦的光响应度、4.8×10琼斯的探测率以及79.5分贝的线性动态范围，这些性能优于基于CoPc和平坦GaN（CoPc/平坦GaN）的光电探测器。高性能主要归因于在CoPc薄膜与纳米多孔GaN的界面处产生的内建电场（BEF），以及GaN的纳米多孔结构，该结构允许更高的光吸收率。此外，该器件表现出优异的稳定性，即使在3个月后，其光电性能和开/关切换行为仍保持不变。
