Highly sensitive photodetectors with single photon level detection is one of the key components to a range of emerging technologies, in particular the ever-growing field of optical communication, remote sensing, and quantum computing. Currently, most of the single-photon detection technologies require external biasing at high voltages and/or cooling to low temperatures, posing great limitations for wider applications. Here, we demonstrate InP nanowire array photodetectors that can achieve single-photon level light detection at room temperature without an external bias. We use top-down etched, heavily doped p-type InP nanowires and n-type AZO/ZnO carrier selective contact to form a radial p-n junction with a built-in electric field exceeding 3x10^5 V/cm at 0 V. The device exhibits broadband light sensitivity and can distinguish a single photon per pulse from the dark noise at 0 V, enabled by its design to realize near-ideal broadband absorption, extremely low dark current, and highly efficient charge carrier separation. Meanwhile, the bandwidth of the device reaches above 600 MHz with a timing jitter of 538 ps. The proposed device design provides a new pathway towards low-cost, high-sensitivity, self-powered photodetectors for numerous future applications.

中文翻译：

---

自供电 InP 纳米线光电探测器，用于室温下的单光子水平检测

具有单光子级检测的高灵敏度光电探测器是一系列新兴技术的关键组件之一，尤其是不断发展的光通信、遥感和量子计算领域。目前，大多数单光子探测技术需要在高电压和/或冷却到低温下进行外部偏置，这对更广泛的应用构成了很大的限制。在这里，我们展示了 InP 纳米线阵列光电探测器，它可以在没有外部偏置的情况下在室温下实现单光子级光探测。我们使用自上而下蚀刻的重掺杂 p 型 InP 纳米线和 n 型 AZO/ZnO 载流子选择性接触来形成径向 pn 结，其内置电场在 0 V 时超过 3x10^5 V/cm。该器件具有宽带光灵敏度，可以将每个脉冲的单个光子与 0 V 的暗噪声区分开来，通过其设计实现近乎理想的宽带吸收、极低的暗电流和高效的电荷载流子分离。同时，器件带宽达到600 MHz以上，时序抖动538 ps。所提出的器件设计为面向未来众多应用的低成本、高灵敏度、自供电光电探测器提供了一条新途径。