Abstract Using silicon nanoporous pillar array (Si-NPA) as substrate, a kind of GaN/Si nanoheterostructure (GaN/Si-NPA) is prepared by depositing GaN nanocrystallites on Si-NPA with chemical vapor deposition method. The morphology characteristics and optical properties of GaN/Si-NPA are investigated systematically. Based on GaN/Si-NPA, a self-powered ultraviolet (UV) photodetector (PD) with device structure of ITO/GaN/Si-NPA/sc-Si/Ag is constructed by depositing ITO on GaN layer and silver on single crystal silicon, respectively. At zero bias voltage without an external power supply, GaN/Si-NPA exhibits a responsivity of 0.072 mA/W, a high current on/off ratio of ∼104 (16 μW/cm2) and fast response speeds of 39.98/40.10 ms under an UV light irradiation at 305 nm. The high performance of GaN/Si-NPA is attributed to the built-in electric field in the heterojunction, which is interpreted via building the energy-band diagrams. The results illustrate that GaN/Si-NPA might be a suitable material system for self-powered UV PDs.

中文翻译：

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基于硅纳米多孔柱阵列的GaN/Si纳米异质结构实现自供电紫外光电探测

摘要 以硅纳米多孔柱阵列（Si-NPA）为衬底，采用化学气相沉积法在Si-NPA上沉积GaN纳米微晶，制备了一种GaN/Si纳米异质结构（GaN/Si-NPA）。系统地研究了GaN/Si-NPA的形貌特征和光学特性。基于GaN/Si-NPA，通过在GaN层上沉积ITO，在单晶上沉积银，构建了具有ITO/GaN/Si-NPA/sc-Si/Ag器件结构的自供电紫外（UV）光电探测器（PD）硅，分别。在没有外部电源的零偏压下，GaN/Si-NPA 表现出 0.072 mA/W 的响应度、~104 (16 μW/cm2) 的高电流开/关比和 39.98/40.10 ms 的快速响应速度305 nm 的紫外光照射。GaN/Si-NPA 的高性能归功于异质结中的内置电场，这是通过构建能带图来解释的。结果表明，GaN/Si-NPA 可能是自供电 UV PD 的合适材料系统。