Many applications require a photodetector (PD) with a large gain to detect very low levels of ultraviolet (UV) light. However, a large gain is generally produced using an impact ionization process, which requires a very large applied voltage. This study demonstrates a photomultiplication (PM)-type UV PD with a simple structure that uses an a-IGZO/p-Si heterojunction. The device exhibits an external quantum efficiency (EQE) of 2565% under 325 nm illumination at a reverse bias of −5 V. The oxygen vacancy (V o ) state in a-IGZO is relaxed to a deep bandgap but is fully occupied by two electrons. V o with doubly charged V o 2+ or singly charged V o + can be excited by UV light. This produces free electrons. There is a high EQE at low reverse-bias because trapped electrons are emitted from the V o . The IGZO/Si heterojunction also has a high response speed (∼1 ms) in the self-powered mode because the built-in poten...

中文翻译：

---

a-IGZO / p-Si异质结紫外光电二极管中的陷阱辅助光电倍增

许多应用需要具有大增益的光电检测器（PD），以检测非常低水平的紫外线（UV）光。然而，通常使用碰撞电离过程产生大的增益，这需要非常大的施加电压。这项研究演示了具有a-IGZO / p-Si异质结的简单结构的光电倍增（PM）型UV PD。该器件在-5 V的反向偏压下在325 nm照射下表现出2565％的外部量子效率（EQE）。a-IGZO中的氧空位（V o）状态被弛豫到深带隙，但被两个原子完全占据电子。带有双电荷V o 2+或单电荷V o +的V o可以被紫外光激发。这产生自由电子。在较低的反向偏置下，EQE较高，因为从V o发射了捕获的电子。