Research Progress of Hefei Plasma Enhanced Wavelength Photoelectric Detector in Anhui Province

【Chinese instrument network instrument research and development】 Recently, Fei Guangtao, researcher of nanomaterials and nanostructures research institute of Institute of Solid Physics, Anhui Hefei Institute of Physical Chemistry, Chinese Academy of Sciences, made progress in the research of plasma-enhanced broad-band photoelectric detectors. Related research The results were published in the Journal of Materials Chemistry C.

Scanning Schematic of Lead Sulfide Film Modified by Gold Nanorod Arrays

As a traditional infrared material, lead sulfide is widely used in infrared detection. In recent years, nanosized lead sulfide materials have been extensively studied and applied to visible light detectors due to their quantum size localization effect, exhibiting excellent performance. For thin-film lead sulfide detectors, their photoelectric response is still not ideal, and the response of the thin film lead sulfide detector needs to be further improved.

The characteristics of IT curves of PbS films modified by PbS thin films (H=0nm) and Au nanorods of different heights (H=30, 60, 90, 120nm) under different laser irradiances. Incident light wavelengths are (a) 450 nm; (b) 532 nm; (c) 660 nm; (d) 980 nm. The optical power is 54.16 mW/cm2.

Common noble metal nanomaterials such as Au, Ag, Pt, Cu, etc., have surface plasmon resonance characteristics and can generate strong electromagnetic field enhancement around them. This plasmon resonance enhancement feature can be applied to photoactive devices such as light emitting diodes, solar cells, photodetectors, photocatalytic systems, and the like. Compared with the disordered noble metal structure, the ordered metal structure can further enhance its surface plasmon resonance effect. Orderly arrangement of noble metal structures such as metal hole arrays, metal antenna arrays, metal grating structures, etc., can adjust their plasmon resonance frequency characteristics by adjusting their periodic structure parameters, thereby achieving the purpose of selective enhancement.

(a) Finite-difference time-domain simulation of the cross-sectional electric field distribution near gold nanorods (H=30, 60, 90, 120 nm); (b) Different heights of Au nanorods (H=30, 60, 90, 120 nm) modified The relative photocurrent growth of PbS films depends on the wavelength of incident light.

Based on the above research status, Fei Guangtao's group of graduate students Xie Binghe et al. used a chemical bath deposition method to prepare PbS thin films, and used an ultra-thin dual-pass titanium dioxide porous membrane as a template to construct ordered Au array/PbS thin film composite photodetectors. Due to the plasmon resonance enhancement effect of the Au array, the response rate of the composite thin-film photodetector is 125-175% higher than that of the pure PbS film detector. Further studies have found that this enhancement exhibits a significant wavelength selectivity. When the height of the gold nanoarray is changed, the strongest enhancement wavelength position of the detector response rate will change, that is, with the height increasing from 30nm to 120nm, the strongest. The enhanced peak position gradually shifts from the visible band (450 nm) to the near-infrared band (980 nm). This work will provide new ideas and approaches for the research and development of plasmon resonance enhanced photodetectors and show potential applications.

The research work was funded by the National Key R&D Project and the National Natural Science Foundation.

(Original title: Hefei Research Institute of plasma enhanced wide-band photodetector research progress)