Zhang Linxiang, Chen Long, Yang Junrui, Liu Jing, Lu Shuaicheng, Liang Xinyi, Zhao Xuezhi, Yang Yang, Hu Jun, Hu Long, Lan Xinzheng, Zhang Jianbing, Gao Liang, Tang Jiang
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, P. R. China.
Optics Valley Laboratory, 1037 Luoyu Road, Wuhan 430074, P. R. China.
Nano Lett. 2023 Jul 26;23(14):6489-6496. doi: 10.1021/acs.nanolett.3c01391. Epub 2023 Jul 11.
Solution-processed colloidal quantum dot (CQD) photodiodes are compatible for monolithic integration with silicon-based readout circuitry, enabling ultrahigh resolution and ultralow cost infrared imagers. However, top-illuminated CQD photodiodes for longer infrared imaging suffer from mismatched energy band alignment between narrow-bandgap CQDs and the electron transport layer. In this work, we designed a new top-illuminated structure by replacing the sputtered ZnO layer with a SnO layer by atomic layer deposition. Benefiting from matched energy band alignment and improved heterogeneous interface, our top-illuminated CQD photodiodes achieve a broad-band response up to 1650 nm. At 220 K, these SnO-based devices exhibit an ultralow dark current density of 3.5 nA cm at -10 mV, reaching the noise limit for passive night vision. The detectivity is 4.1 × 10 Jones at 1530 nm. These SnO-based devices also demonstrate exceptional operation stability. By integrating with silicon-based readout circuitry, our CQD imager realizes water/oil discrimination and see-through smoke imaging.
溶液处理的胶体量子点（CQD）光电二极管与基于硅的读出电路进行单片集成具有兼容性，可实现超高分辨率和超低功耗的红外成像仪。然而，用于长波红外成像的顶部照明CQD光电二极管存在窄带隙CQD与电子传输层之间能带对准不匹配的问题。在这项工作中，我们通过原子层沉积用SnO层替代溅射的ZnO层，设计了一种新的顶部照明结构。受益于匹配的能带对准和改善的异质界面，我们的顶部照明CQD光电二极管实现了高达1650 nm的宽带响应。在220 K时，这些基于SnO的器件在-10 mV下表现出3.5 nA cm的超低暗电流密度，达到了被动夜视的噪声极限。在1530 nm处的探测率为4.1×10 Jones。这些基于SnO的器件还表现出出色的运行稳定性。通过与基于硅的读出电路集成，我们的CQD成像仪实现了水/油鉴别和透视烟雾成像。
