Heterojunction Infrared Photodiodes With High Dynamic Range Based on Lead Sulfide Quantum Dot and Zinc Oxide Nanomembrane

• Published in: IEEE transactions on nanotechnology Vol. 22; pp. 359 - 364
• Main Authors: Wang, Hailu, Dong, Yi, Fu, Xiao, Zhao, Xuezhi, Zhao, Qixiao, Xia, Mengjia, Kang, Mengyang, Zhao, Chaoyu, Xu, Zhihao, Zhu, Yicheng, Gao, Liang, Tang, Jiang, Dong, Lixin, Miao, Jinshui, Hu, Weida
• Format: Journal Article
• Language: English
• Published: New York IEEE 2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Absorption; colloidal quantum dots; Colloiding; Dynamic range; Electric fields; Energy gap; Focal plane devices; Group III-V semiconductors; Heterojunctions; Heterostructures; Holes (electron deficiencies); II-VI semiconductor materials; Infrared absorption; infrared photodetectors; Integrated circuits; Lead; Lead sulfide (PbS); Lead sulfides; linear dynamic range; Photoconductivity; Photodiodes; Photoelectric effect; Photoelectric emission; Photometers; Quantum dots; Scanning electron microscopy; Short circuits; Short wave radiation; Thin films; visible and infrared imaging; Zinc oxide; Zinc oxides
• ISSN: 1536-125X; 1941-0085
• DOI: 10.1109/TNANO.2023.3292258

Photodetectors and imagers with short-wave infrared (SWIR) sensitivities at wavelengths beyond the bandgap of silicon ( E g ∼ 1.1 eV) are currently subject to a rapidly expanding application space. Despite continued technological advancement, linear dynamic range and high costs associated with processing III-V semiconductors still limit their widespread usage. Solution-processed colloidal quantum dots (CQDs) - with tunable bandgap and strong light-matter interaction - are highly suitable as infrared absorbers for cost-effective photodetection. Here, we demonstrate a SWIR photodiode architecture with n-type zinc oxide (ZnO) nanomembrane and p-type lead sulfide (PbS) CQD thin film vertically stacked together. In the PbS CQD/ZnO nanomembrane p-n photodiode, the incident SWIR photons can be absorbed in the PbS CQD film and the photoexcited electron-hole pairs are rapidly separated by the built-in electric field. The fabricated heterojunction p-n photodiodes show a broad short-circuit photocurrent response with a peak responsivity of ∼75 mA/W and a maximum linear dynamic range of ∼100 dB. Finally, to demonstrate the uniformity and scalability, 16 × 16 photodetectors arrays (256 pixels) have been realized showing a very uniform photocurrent response with I sc in the range of 100 nA. As the increased maturity of large-scale film fabrication of PbS CQD along with CMOS readout integrated circuit technology, focal plane arrays can be realized based on PbS CQD/ZnO nanomembrane heterostructures.