Chinese Journal of Applied Chemistry ›› 2025, Vol. 42 ›› Issue (8): 1078-1086.DOI: 10.19894/j.issn.1000-0518.250035

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Controllable Preparation of CdS@PbS Core/Shell Quantum Dots via Cation Exchange and Their Near-Infrared Photodetector

Xiao-Li LI, Yan-Li LI, Dong LI()   

  1. Technology Innovation Center of Nanosized Natural Products and New Materials of Hebei Province,Heber Center for New Inorganic Optoelectronic Nanomaterial Research,School of Chemical Engineering and Materials,Handan University,Handan 056005,China
  • Received:2025-01-19 Accepted:2025-06-04 Published:2025-08-01 Online:2025-08-11
  • Contact: Dong LI
  • About author:lidong@bit.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(22171062);the Natural Science Foundation of Hebei Province of China(B2021109002);the Handan Science and Technology Research and Development Program(23422404149ZC);the On-campus Projects of Handan University(XZ2022201)

Abstract:

The CdS quantum dots (QDs) were converted into CdS@PbS core-shell QDs with near-infrared (NIR) absorption capacity by cation exchange strategy in N,N-dimethylformamide (DMF) solvent. We characterized the morphology, elemental composition, crystal structure and optical properties of CdS@PbS core-shell QDs by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and UV-Vis-NIR spectrophotometer. Considering their unique NIR absorption properties, these CdS@PbS core-shell QDs were specially utilized for fabricating self-powered photoelectrochemical-type NIR photodetector (PD). The PDs exhibit an excellent photoresponse performance under 850 nm illumination, with a typical on/off ratio of 2277, a responsivity of 83.3 mA/W, and a detectivity of 2.91×1011 Jones. Notably, the PD shows a good linear relationship between the photocurrent and the incident light intensity, indicating that the device can achieve stable detection under 850 nm illumination with different light intensities.

Key words: Near-infrared photodetector, Self-powered, CdS@PbS core/shell quantum dots, Cation exchange strategy

CLC Number: