Ligand-Engineered HgTe Colloidal Quantum Dot Solids for Infrared Photodetectors

作者：Yang, Ji; Hu, Huicheng; Lv, Yifei; Yuan, Mohan; Wang, Binbin; He, Ziyang; Chen, Shiwu; Wang, Ya; Hu, Zhixiang; Yu, Mengxuan; Zhang, Xingchen; He, Jungang; Zhang, Jianbing; Liu, Huan; Hsu, Hsien-Yi; Tang, Jiang; Song, Haisheng^*; Lan, Xinzheng^*

来源：Nano Letters, 2022, 22(8): 3465-3472.

DOI：10.1021/acs.nanolett.2c00950

• HgTe colloidal quantum dots
• monodispersity
• ligand engineering
• carrier mobility
• infrared photodetectors

HgTe colloidal quantum dots (CQDs) arepromising absorber systems for infrared detection due to theirwidely tunable photoresponse in all infrared regions. Up to now,the best-performing HgTe CQD photodetectors have relied onusing aggregated CQDs, limiting the device design, uniformity andperformance. Herein, we report a ligand-engineered approach thatproduces well-separated HgTe CQDs. The present strategyfirstemploys strong-binding alkyl thioalcohol ligands to enable thesynthesis of well-dispersed HgTe cores, followed by a secondgrowth process and afinal postligand modification step enhancingtheir colloidal stability. We demonstrate highly monodisperseHgTe CQDs in a wide size range, from 4.2 to 15.0 nm with sharp excitonic absorption fully covering short- and midwave infraredregions, together with a record electron mobility of up to 18.4 cm2V-1s-1. The photodetectors show a room-temperature detectivityof 3.9x1011jones at a 1.7 mu m cutoffabsorption edge

• 单位
  华中科技大学; 武汉工程大学