Feng Yajun, Chang Huicong, Liu Yingbo, Guo Nan, Liu Junku, Xiao Lin, Li Lishuo
School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, People's Republic of China.
Nanophotonics and Optoelectronics Research Center, Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094, People's Republic of China.
Nanotechnology. 2021 May 7;32(19):195602. doi: 10.1088/1361-6528/abde64.
Quantum dots (QDs) are promising materials used for room temperature mid-infrared (MIR) photodetector due to their solution processing, compatibility with silicon and tunability of band structure. Up to now, HgTe QDs is the most widely studied material for MIR detection. However, photodetectors assembled with HgTe QDs usually work under cryogenic cooling to improve photoelectric performance, greatly limiting their application at room temperature. Here, less-toxic SnTe QDs were controllably synthesized with high crystallinity and uniformity. Through proper ligand exchange and annealing treatment, the photoconductive device assembled with SnTe QDs demonstrated ultralow dark current and broadband photo-electric response from visible light to 2 μm at room temperature. In addition, the visible and near infrared photo-electric performance of the SnTe QDs device were well maintained even standing 15 d in air. This excellent performance was due to the effective protection of the ligand on surface of the QDs and the effective transport of photo-carriers between the SnTe interparticles. It would provide a new idea for environmentally friendly mid-IR photodetectors working at room temperature.
量子点（QDs）因其可溶液加工、与硅的兼容性以及能带结构的可调性，是用于室温中红外（MIR）光电探测器的有前景的材料。到目前为止，HgTe量子点是用于MIR探测研究最广泛的材料。然而，用HgTe量子点组装的光电探测器通常在低温冷却下工作以提高光电性能，这极大地限制了它们在室温下的应用。在此，可控合成了具有高结晶度和均匀性的低毒SnTe量子点。通过适当的配体交换和退火处理，用SnTe量子点组装的光电器件在室温下表现出超低暗电流以及从可见光到2μm的宽带光电响应。此外，SnTe量子点器件的可见光和近红外光电性能即使在空气中放置15天也能很好地保持。这种优异的性能归因于量子点表面配体的有效保护以及光载流子在SnTe颗粒间的有效传输。这将为在室温下工作的环境友好型中红外光电探测器提供新思路。
