Short-wavelength-infrared (SWIR; 1.4–3.0 µm) photodetection is important for various applications. Inducing a low-cost silicon-compatible material, such as germanium, to detect SWIR light would be advantageous for SWIR applications compared with using conventional (III-V or II-VI) SWIR materials. Here, we present a scalable nonequilibrium method for hyperdoping germanium with gold for dopant-mediated SWIR photodetection. Using ion implantation followed by nanosecond pulsed laser melting, we obtain a single-crystal material with a peak gold concentration of 3 × ${10}^{19}{\mathrm{cm}}^{-3}$ $({10}^3$ times the solubility limit). This hyperdoped germanium has fundamentally different optoelectronic properties from those of intrinsic and conventionally doped germanium. This material exhibits sub-band-gap absorption of light up to wavelengths of at least 3 µm, with a sub-band-gap optical absorption coefficient comparable to that of commercial SWIR photodetection materials. We show that germanium hyperdoped with gold exhibits sub-band-gap SWIR photodetection at room temperature, in contrast with previous doped-germanium photodetector studies, which only show a low-temperature response. This material is a potential pathway to low-cost room-temperature silicon-compatible SWIR photodetection.

中文翻译：

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具有室温子带隙光电响应的金掺杂锗

短波长红外（SWIR; 1.4-3.0  μ M）光检测是用于各种应用的重要的。与使用常规（III-V或II-VI）SWIR材料相比，诱导低成本的硅兼容材料（如锗）来检测SWIR光对于SWIR应用将是有利的。在这里，我们提出了一种可扩展的非平衡方法，用于以金超掺杂锗，用于掺杂剂介导的SWIR光检测。使用离子注入，然后进行纳秒脉冲激光熔化，我们获得了峰值金浓度为3×的单晶材料。 ${10}^{19}{\mathrm{厘米}}^{-3}$ $（{10}^3$乘以溶解度极限）。这种高掺杂的锗与本征和常规掺杂的锗具有根本不同的光电特性。该材料对至少3 µm的波长的光具有亚带隙吸收能力 ，其亚带隙光学吸收系数可与商业SWIR光检测材料相媲美。我们表明，与先前仅显示低温响应的先前掺杂锗光电探测器研究相比，高掺杂锗的锗在室温下表现出亚带隙SWIR光检测。这种材料是通往低成本室温硅兼容SWIR光电检测的潜在途径。