Singh Subhash C, Peng Yao, Rutledge James, Guo Chunlei
The Institute of Optics, University of Rochester, Rochester, New York 14627, United States.
Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Changchun, China.
ACS Appl Electron Mater. 2019 Jul 23;1(7):1169-1178. doi: 10.1021/acsaelm.9b00174. Epub 2019 Jun 24.
The development of a highly responsive, near-zero-biased broadband photo and thermal detector is required for self-powered night vision security, imaging, remote sensing, and space applications. Photothermal-effect-based photodetectors operate on the principle of photothermal heating and can sense radiation from the UV to IR spectral region for broadband photo and thermal detection. This type of photodetector is highly desirable, but few materials have been shown to meet the stringent requirements including broadband optical/thermal absorption with high absorption coefficients, low thermal conductivity, and a large Seebeck coefficient. Here, we demonstrate ultraresponsive, near-zero-biased photodetectors made of mass-producible Cu Se nanomaterials. Our photodetectors are fabricated with powder pressing and operate on the principle of negative photoconductivity that utilizes the Seebeck effect under the combined effects of Joule and photothermal heating to detect extremely low levels of broadband optical radiation. We show that copper-deficient CuSe and selenium-deficient CuSe copper selenide materials have negative photoconductivity. However, stochiometric CuSe copper selenide shows positive photoconductivity. We demonstrate that a photodetector made from the Ag:n-CuSe:p-Ag:n system has the best photoresponse and generates a 520 mA/mm negative photocurrent and a high responsivity of 621 A/W under low bias.
自供电夜视安全、成像、遥感和太空应用需要开发一种高响应性、近零偏置的宽带光热探测器。基于光热效应的光探测器基于光热加热原理工作，能够感测从紫外到红外光谱区域的辐射，用于宽带光热探测。这种类型的光探测器非常理想，但很少有材料能满足包括具有高吸收系数的宽带光/热吸收、低导热率和大塞贝克系数在内的严格要求。在此，我们展示了由可大规模生产的 CuSe 纳米材料制成的超响应、近零偏置光探测器。我们的光探测器通过粉末压制制成，基于负光电导原理工作，该原理利用焦耳热和光热加热的联合效应下的塞贝克效应来检测极低水平的宽带光辐射。我们表明，缺铜的 CuSe 和缺硒的 CuSe 硒化铜材料具有负光电导性。然而，化学计量比的 CuSe 硒化铜表现出正光电导性。我们证明，由 Ag:n-CuSe:p-Ag:n 系统制成的光探测器具有最佳的光响应，在低偏置下产生 520 mA/mm 的负光电流和 621 A/W 的高响应率。
