PbSe materials, with their narrow bandgap, excellent optical absorption and outstanding optical response, are ideal for infrared photodetectors, exhibiting unique advantages in optical communication, infrared imaging and thermal detection. Nevertheless, PbSe typically has a non-layered crystal structure and inherent isotropy, making the synthesis of low-dimensional nanomaterials challenging. Besides, PbSe photoconductive detectors suffer from high dark current due to intrinsic defects and thermally excited carriers, which is detrimental to device performance. Here, we utilized physical vapor deposition (PVD) method to grow high-quality PbSe nanosheets and combined them with two-dimensional (2D) transition metal dichalcogenides (TMDs) material WSe₂ to fabricate a self-powered PbSe/WSe₂ p-n heterostructure photodetector. Under illumination with a 650 nm laser at a power density of 128.97 mW/cm² and 0 V bias, the PbSe/WSe₂ heterojunction device exhibited significant photovoltaic characteristics and generated a short-circuit current of 161.7 nA. Furthermore, under 0.02 mW/cm² of 650 nm laser illumination at 0 V bias, the device achieved an excellent responsivity (R) of 15.6 A/W and a specific detectivity (D*) of 1.08×10¹¹ Jones. And the response speed of the heterojunction device at 0 V (511 μs/74 μs) was three orders of magnitude faster than that of PbSe nanosheets (93 ms/104 ms). The device also demonstrated broadband detection capabilities from 405 nm to 1550 nm and excellent imaging performance in the near-infrared region at 0 V bias. In summary, the outstanding photoelectric detection performance and imaging capabilities of the PbSe/WSe₂ heterojunction nanosheet detector indicate its significant potential for applications in miniaturized, low-noise, broadband, high-speed and high-performance photodetectors.

中文翻译：

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用于图像传感的高性能自供电 PbSe/WSe2 p-n 异质结光电探测器


PbSe 材料具有窄带隙、优异的光吸收和出色的光响应，是红外光电探测器的理想选择，在光通信、红外成像和热探测方面表现出独特的优势。然而，PbSe 通常具有非层状晶体结构和固有的各向同性，这使得低维纳米材料的合成具有挑战性。此外，PbSe 光电导探测器由于本征缺陷和热激发载流子而受到高暗电流的影响，这对器件性能不利。在这里，我们利用物理气相沉积 （PVD） 方法生长高质量的 PbSe 纳米片，并将它们与二维 （2D） 过渡金属硫化物 （TMD） 材料 WSe ₂ 相结合，制造了自供电的 PbSe/WSe ₂ p-n 异质结构光电探测器。在功率密度为 128.97 mW/cm ² 和 0 V 偏置的 650 nm 激光器照射下，PbSe/WSe ₂ 异质结器件表现出明显的光伏特性，并产生了 161.7 nA 的短路电流。此外，在 0 ² V 偏置的 650 nm 激光照射下，该器件实现了 15.6 A/W 的出色响应度 （R） 和 1.08×10 ¹¹ Jones 的特异性探测率 （D*）。异质结器件在 0 V 时的响应速度 （511 μs/74 μs） 比 PbSe 纳米片 （93 ms/104 ms） 快三个数量级。该器件还展示了 405 nm 至 1550 nm 的宽带检测能力，以及在 0 V 偏置时在近红外区域具有出色的成像性能。 综上所述，PbSe/WSe ₂ 异质结纳米片探测器出色的光电探测性能和成像能力表明其在小型化、低噪声、宽带、高速和高性能光电探测器中的应用潜力巨大。