Picosecond Time Resolution with Avalanche Amorphous Selenium
Picosecond Time Resolution with Avalanche Amorphous Selenium
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DOI：
10.1021/acsphotonics.9b00012
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发表时间：
2019-06-01
期刊：
影响因子：
7
通讯作者：
Goldan, Amir H.
中科院分区：
文献类型：
--
作者：
LaBella, Andy;Stavro, Jann;Goldan, Amir H.
超快光电检测传统上是使用晶体光电探测器进行的，但晶体光电探测器往往存在产量低、检测效率欠佳以及限制其潜在应用的操作限制等问题。非晶硒是一种独特的无序光敏材料，其中载流子传输可以完全从局域态转移到空穴变热的扩展态，从而导致确定性的非马尔可夫碰撞电离雪崩，使硒表现出类似于晶体光电导体的特性。我们首次使用纳米柱制造了多孔硒探测器，可实现雪崩增益和单极时间差分电荷传感。我们通过实验展示了这些功能如何共同将 Selenium 的时间性能提高了近 4 个数量级，从而使我们能够实现适合各种超快应用的皮秒定时抖动。这种探测器对于皮秒光电探测和成像来说是一种可行的低成本、高产量的替代方案。
Ultrafast photodetection has traditionally been performed with crystalline photodetectors, which tend to suffer from low production yield, suboptimal detection efficiency, and operational limitations that restrict their potential applications. Amorphous selenium is a unique, disordered photosensing material in which carrier transport can be shifted entirely from localized to extended states where holes get hot, resulting in deterministic, non-Markovian impact ionization avalanche, causing selenium to exhibit characteristics similar to crystalline photoconductors. For the first time, we have fabricated a multiwell selenium detector using nanopillars that achieves both avalanche gain and unipolar time-differential charge sensing. We experimentally show how these features together improve selenium's temporal performance by nearly 4 orders of magnitude, allowing us to achieve picosecond timing jitter suitable for a variety of ultrafast applications. Such a detector would be a viable low-cost, high production yield alternative for picosecond photodetection and imaging.