Infrared PbS quantum dot (QD) photodiodes play a vital role in various applications, including photovoltaics, light‐emitting diodes, lasers, and photodetectors. Despite their superior potential, high‐performance all‐QD homojunction photodiodes with bifacial structures have yet to be reported. Here, post‐treatment ligand engineering is successfully employed to precisely tune the doping dipoles of PbS QDs, transitioning them from n‐type, through intrinsic, to p‐type. All‐QD homojunction photodiodes solar cells with a n‐i‐p architecture are constructed by integrating three types of PbS QD layers of 1.37 eV bandgaps with controllable doping dipoles, which delivers a power conversion efficiency of 10.0%, among the highest values reported in PbS all‐QD homojunction solar cells so far. Owing to symmetry all‐QD architecture, bifacial PbS all‐QDs photodiodes, using 1.37 eV bandgap PbS QDs as both n‐type and p‐type charge transport layers and 0.90 eV bandgap PbS QDs as intrinsic light absorber layers, achieved an almost ideal bifactor approaching 93% and decent detectivities of 1.63 × 1011 Jones from ITO illumination and 1.86 × 1011 Jones from silver nanowire (Ag NW) illumination at 1370 nm. Therefore, this work provides a facile approach for the design of bifacial all‐QD homojunction photodiodes, broadening their potential applications in advanced QD optoelectronic systems.

中文翻译：

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Ligand Engineering 实现双面 PbS 全 QD 同质结光电二极管


红外 PbS 量子点 （QD） 光电二极管在各种应用中发挥着至关重要的作用，包括光伏、发光二极管、激光器和光电探测器。尽管具有双面结构的高性能全 QD 同质结光电二极管具有卓越的潜力，但尚未报道。在这里，成功地采用处理后配体工程来精确调节 PbS QD 的掺杂偶极子，将它们从 n 型过渡到本征型，再到 p 型。具有 n-i-p 结构的全 QD 同质结光电二极管太阳能电池是通过将三种类型的 1.37 eV 带隙的 PbS QD 层与可控掺杂偶极子集成在一起而构建的，可提供 10.0% 的功率转换效率，是迄今为止 PbS 全 QD 同质结太阳能电池中报道的最高值之一。由于对称的全量子点架构，双面 PbS 全量子点光电二极管使用 1.37 eV 带隙 PbS QD 作为 n 型和 p 型电荷传输层，使用 0.90 eV 带隙 PbS QD 作为本征光吸收层，在 1370 nm 处实现了接近 93% 的近乎理想的双因子和 1.63 × 1011 Jones 的检测率和 1.86 × 1011 Jones 的银纳米线 （Ag NW） 照明。因此，这项工作为双面全 QD 同质结光电二极管的设计提供了一种简便的方法，拓宽了它们在先进 QD 光电系统中的潜在应用。