具有无掺杂倍增区的黑硅雪崩光电二极管实现超过98%的外量子效率
Black silicon avalanche photodiode with dopant-free multiplication region achieves >98% EQE
- Aalto University（阿尔托大学）
- ElFys Inc.（ElFys公司）
机构由 AI 辅助整理，请以论文原文为准。
中文总结 AI 辅助
本研究通过黑硅纳米结构与Al2O3诱导载流子收集，在倒台面APD中实现无掺杂倍增区，使EQE在紫外波段超过100%，并能探测每个单光子。
中文摘要 AI 辅助
传统硅雪崩光电二极管（Si APD）依赖高掺杂区来实现碰撞电离并获得内部增益。然而，这些区域中低效的电荷收集，加上前表面反射，降低了这些器件的外量子效率（EQE）。在本工作中，我们通过在倒台面Si APD结构中集成黑硅（b-Si）表面纳米结构与Al2O3诱导的载流子收集，同时缓解了这两种损耗机制。该设计在不需离子注入的情况下限定了电场并定义了倍增区。所得器件在紫外-可见光谱范围内表现出接近理想的响应度（在M=1时），在200-400纳米范围内EQE超过100%（峰值约130%），在400-700纳米范围内EQE为92-100%。在80V、100V和接近击穿的约110V时，分别获得M约4、M约10和M约23的雪崩增益。暗电流在约80V以下保持在皮安范围，但在接近击穿时升至纳安范围，收窄了实际偏压窗口。对于直径为1-5毫米的器件，测得电容限制的上升时间约为30-570纳秒。结果表明，所开发的架构使APD能够在宽波长范围内检测每一个单光子。
英文摘要
Conventional silicon avalanche photodiodes (Si APDs) rely on highly doped regions to enable impact ionization and achieve internal gain. However, inefficient charge collection in these regions, combined with front surface reflection, degrades the external quantum efficiency (EQE) of these devices. In this work, we mitigate both loss mechanisms by integrating black silicon (b-Si) surface nanostructuring with Al2O3 induced carrier collection in an inverted-mesa Si APD architecture. This design confines the electric field and defines the multiplication region without requiring ion implantation. The resulting devices display near-ideal responsivity (at M = 1) across the UV-visible spectrum, with EQE exceeding 100% at 200-400 nm (peak ~130%) and exhibiting 92-100% at 400-700 nm. Avalanche gains of M ~ 4 at 80 V, M ~ 10 at 100 V, and M ~ 23 near breakdown at ~110 V are obtained. Dark current remains in the picoampere range up to ~80 V but rises to the nanoampere range near breakdown, narrowing the practical bias window. Capacitance-limited rise times of ~30-570 ns are measured for device diameters of 1-5 mm. The results demonstrate that the developed architecture enables APDs capable of detecting every single photon over wide range of wavelengths.
