InGaAs-based photodetectors have been generally used for detection in the short-wave infrared (SWIR) region. However, the epitaxial process used to grow these materials is expensive; therefore, InGaAs-based photodetectors are limited to space exploration and military applications. Many researchers have expended considerable efforts to address the problem of SWIR photodetector development using lead sulfide (PbS) quantum dots (QDs). Along with their cost-efficient solution processability and flexible substrate compatibility, PbS QDs are highly interesting for the quantum-size-effect tunability of their bandgaps, spectral sensitivities, and wide absorption ranges. However, the performance of PbS QD-based SWIR photodetectors is limited owing to inefficient carrier transfer and low photo and thermal stabilities. In this study, a simple method is proposed to overcome these problems by incorporating CdS in PbS QD shells to provide efficient carrier transfer and enhance the long-term stability of SWIR photodetectors against oxidation. The SWIR photodetectors fabricated using thick-shell PbS/CdS QDs exhibited a high on/off (light/dark) ratio of 11.25 and a high detectivity of 4.0 × 1012 Jones, which represents a greater than 10 times improvement in these properties relative to those of PbS QDs. Moreover, the lifetimes of thick-shell PbS/CdS QD-based SWIR photodetectors were significantly improved owing to the self-passivation of QD surfaces.

中文翻译：

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采用改良的核/壳胶体量子点的空气稳定且超灵敏的溶液浇铸SWIR光电探测器。

基于InGaAs的光电探测器已普遍用于短波红外（SWIR）区域的探测。然而，用于生长这些材料的外延工艺是昂贵的。因此，基于InGaAs的光电探测器仅限于太空探索和军事应用。许多研究人员已投入大量精力来解决使用硫化铅（PbS）量子点（QD）的SWIR光电探测器开发问题。除了具有成本效益的解决方案可加工性和灵活的基板兼容性外，PbS QD还因其带隙的量子尺寸效应可调谐性，光谱灵敏度和宽吸收范围而引起人们的极大兴趣。但是，由于载流子转移效率低以及光和热稳定性低，基于PbS QD的SWIR光电探测器的性能受到限制。在这个研究中，提出了一种简单的方法来克服这些问题，方法是将CdS掺入PbS QD外壳中，以提供有效的载流子传输并增强SWIR光电探测器抗氧化的长期稳定性。使用厚壳PbS / CdS QD制成的SWIR光电探测器显示出11.25的高开/关（亮/暗）比和4.0×1012 Jones的高探测率，与这些特性相比，其性能提高了10倍以上PbS QD。此外，由于QD表面的自钝化，基于QD的厚壳PbS / CdS QD的SWIR光电探测器的寿命得到了显着提高。使用厚壳PbS / CdS QD制成的SWIR光电探测器显示出11.25的高开/关（亮/暗）比和4.0×1012 Jones的高探测率，与这些特性相比，其性能提高了10倍以上PbS QD。此外，由于QD表面的自钝化，基于QD的厚壳PbS / CdS QD的SWIR光电探测器的寿命得到了显着提高。使用厚壳PbS / CdS QD制成的SWIR光电探测器显示出11.25的高开/关（亮/暗）比和4.0×1012 Jones的高探测率，与这些特性相比，其性能提高了10倍以上PbS QD。此外，由于QD表面的自钝化，基于QD的厚壳PbS / CdS QD的SWIR光电探测器的寿命得到了显着提高。