Photodetection over a broad spectral range is necessary for multispectral sensing and imaging. Despite the fact that broadband single-element detectors with high performance have been demonstrated with various low-dimensional materials, broadband focal plane array imagers have been rarely reported. Here we propose a stacked lead sulfide/mercury telluride colloidal quantum dot photodetector configuration with optimized graded energy gaps. This architecture allows for ultrabroadband spectral response from 0.4 to 5.0 µm, with responsivity values of 0.23, 0.31, 0.83 and 0.71 A W⁻¹ at 0.4, 0.7, 2.2 and 4.2 µm, respectively. We also fabricate a focal plane array imager with a resolution of 640 × 512, a low photoresponse non-uniformity down to 6% and a noise equivalent temperature difference as low as 34 mK. We demonstrate broadband imaging by simultaneously capturing both short-wave infrared and mid-wave infrared information, as well as multispectral imaging in the red, green, blue, short-wave infrared and mid-wave infrared channels, using a set of optical filters.

宽光谱范围内的光电检测对于多光谱传感和成像是必要的。尽管已经用各种低维材料证明了高性能的宽带单元件探测器，但宽带焦平面阵列成像器却很少报道。在这里，我们提出了一种具有优化分级能隙的堆叠硫化铅/碲化汞胶体量子点光电探测器配置。该架构可实现 0.4 至 5.0 µm 的超宽带光谱响应，在 0.4、0.7、2.2 和 4.2 µm 处的响应度值分别为 0.23、0.31、0.83 和 0.71 AW ^-1 。我们还制造了分辨率为 640 × 512、光响应不均匀性低至 6%、噪声等效温差低至 34 mK 的焦平面阵列成像器。我们通过使用一组滤光片同时捕获短波红外和中波红外信息以及红、绿、蓝、短波红外和中波红外通道的多光谱成像来演示宽带成像。