近日，北京理工大学的陈梦璐及其研究团队取得一项新进展。经过不懈努力，他们成功研制出波长达18μm的甚长波红外量子点光电探测器。相关研究成果已于2024年4月12日在国际知名学术期刊《光：科学与应用》上发表。

在这项研究中，研究人员通过结合再生长技术和离子掺杂改性方法，成功地在HgTe CQD上实现了高达18μm波长的光检测。在液氮温度下，该材料对于18μm和10μm波长的光导体，其响应率分别达到了0.3A/W和0.13A/W，而对应的比探测率则分别为6.6×10⁸ Jones和2.3×10⁹ Jones。这项研究是解答关于CQD光探测波长限制这一普遍疑问的重要一步。

据悉，胶体量子点（CQDs）因其在高通量溶液处理方面的潜力和从紫外到红外波长的宽能隙可调性，已成为光电子器件领域的研究热点。然而，关于CQD波长区域的上限，人们仍存在疑虑。虽然目前CQD的吸收能力已延伸至太赫兹范围，但实际光探测的波长仍主要局限于中波红外。因此，揭示CQD在更长波长下的光响应特性，是探索这些纳米材料终极性能的关键挑战。此外，这一挑战也激发了人们对自下而上红外光探测技术的兴趣，因为相较于外延生长的半导体，这种方法的成本降低了近10%。

附：英文原文

Title: Very long wave infrared quantum dot photodetector up to 18 μm

Author: Xue, Xiaomeng, Hao, Qun, Chen, Menglu

Issue&Volume: 2024-04-12

Abstract: Colloidal quantum dots (CQDs) are of interest for optoelectronic devices because of the possibility of high-throughput solution processing and the wide energy gap tunability from ultraviolet to infrared wavelengths. People may question about the upper limit on the CQD wavelength region. To date, although the CQD absorption already reaches terahertz, the practical photodetection wavelength is limited within mid-wave infrared. To figure out challenges on CQD photoresponse in longer wavelength, would reveal the ultimate property on these nanomaterials. What’s more, it motivates interest in bottom-up infrared photodetection with less than 10% cost compared with epitaxial growth semiconductor bulk. In this work, developing a re-growth method and ionic doping modification, we demonstrate photodetection up to 18μm wavelength on HgTe CQD. At liquid nitrogen temperature, the responsivity reaches 0.3A/W and 0.13A/W, with specific detectivity 6.6×10⁸ Jones and 2.3×10⁹ Jones for 18μm and 10μm CQD photoconductors, respectively. This work is a step toward answering the general question on the CQD photodetection wavelength limitation.

DOI: 10.1038/s41377-024-01436-y

Source: https://www.nature.com/articles/s41377-024-01436-y