Chen Menglu, Hao Qun, Luo Yuning, Tang Xin
School of Optics and Photonics, Beijing Institute of Technology, No. 5, Zhongguancun South Street, Beijing, 100081, China.
Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, Beijing, 100081, China.
ACS Nano. 2022 Jul 26;16(7):11027-11035. doi: 10.1021/acsnano.2c03631. Epub 2022 Jul 6.
In this work, a room-temperature mixed-phase ligand exchange method is developed to obtain a relatively high carrier mobility (∼1 cm/(V s)) on HgSe intraband colloidal quantum dot solids without any observable trap state. What is more, the doping from 1S to 1P state in the conduction band could be precisely controlled by additional salts during this method, proved by optical and transport experiments. The high mobility and controllable doping benefit the mid-infrared photodetector utilizing the 1S to 1P transition, with a 1000-fold improvement in response speed, which is several μs, a 55-fold increase in responsivity, which is 77 mA/W, and a 10-fold increase in specific detectivity, which is above 1.7 × 10 Jones at 80 K. The high-performance photodetector could serve as an intraband infrared camera for thermal imaging, as well as a CO gas sensor with a range from 0.25 to 2000 ppm.
在这项工作中，开发了一种室温混合相配体交换方法，以在HgSe带内胶体量子点固体上获得相对较高的载流子迁移率（约1 cm/(V·s)），且没有任何可观察到的陷阱态。此外，在此方法中，通过额外的盐可以精确控制导带中从1S到1P态的掺杂，这已通过光学和输运实验得到证明。高迁移率和可控掺杂有利于利用1S到1P跃迁的中红外光电探测器，其响应速度提高了1000倍，达到几微秒，响应度提高了55倍，达到77 mA/W，比探测率提高了10倍，在80 K时高于1.7×10 Jones。这种高性能光电探测器可作为用于热成像的带内红外相机，以及范围为0.25至2000 ppm的CO气体传感器。
