Effective suppression of dark current is essential for improving the performance of bulk defect-mediated absorption (BDA) photodetectors. Blocked impurity band (BIB) infrared detectors have been developed and utilized from mid-infrared to far-infrared wavelength regions for low noise. In this work, a blocking layer of dark current was applied to a BDA short-wave infrared (SWIR) photodetector, emulating the concept of BIB detectors. ZnO was chosen as the blocking layer to impede the transport of electrons from the bulk defect levels due to its wide bandgap and to allow the photocurrent to remain nearly unaffected by proper positioning of the conduction band minimum. After introducing the ZnO blocking layer, the dark current density of the photodetector was reduced by two orders of magnitude, and the specific detectivity was enhanced by one order of magnitude. The effects of TiO2 and WO3 as blocking layers were also investigated and compared with ZnO. This work offers an effective method for enhancing detectivity in SWIR BDA photodetection by suppressing the dark current efficiently.

中文翻译：

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用于硅基短波红外光探测的暗电流阻挡层


有效抑制暗电流对于提高体缺陷介导吸收 （BDA） 光电探测器的性能至关重要。已经开发并使用了从中红外到远红外波长区域的阻闭杂质带 （BIB） 红外检测器，以实现低噪声。在这项工作中，将暗电流阻挡层应用于 BDA 短波红外 （SWIR） 光电探测器，模拟了 BIB 探测器的概念。选择 ZnO 作为阻塞层，由于其宽带隙，阻止电子从体缺陷水平传输，并允许光电流几乎不受导带最小值的正确定位的影响。引入 ZnO 阻挡层后，光电探测器的暗电流密度降低了两个数量级，比探测率提高了一个数量级。还研究了 TiO2 和 WO3 作为阻塞层的影响，并与 ZnO 进行了比较。本研究通过有效抑制暗电流，为提高 SWIR BDA 光探测的探测能力提供了一种有效的方法。