Enhancement of electrical properties by CuS–PVPnanocomposite on the ZnO/polymer heterojunction

Autor: Verma, Bandhna, Hmar, Jehova Jire L., Swart, H. C., Kumar, Vinay
Zdroj: Journal of the Chinese Chemical Society; July 2024, Vol. 71 Issue: 7 p672-683, 12p
Abstrakt: A nanocomposite matrix of covellite–polyvinylpyrrolidone (CuS–PVP) was synthesized through a solution processing method and applied via spin coating onto hydrothermally grown zinc oxide (ZnO) nanorods. Characterization techniques, including X‐ray powder diffraction and scanning electron microscopy, confirmed the successful decoration of chain‐like CuS–PVP polymer composites onto hexagonal ZnO nanorods. The UV‐vis spectroscopy revealed an absorption peak at 372 nm, indicating excitonic absorption of ZnO, and a reduction in the band gap from 3.11 to 2.59 eV upon CuS–PVP polymer decoration, enhancing light harvesting efficiency. Photoluminescence spectra demonstrated the lowest charge carrier recombination rate in the ZnO/CuS–PVP sample, promoting efficient charge separation and transportation, supported by Fourier‐transform infrared analysis indicating chemical bonding. Subsequently, the impact of CuS–PVP as an insertion layer in the ZnO/poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) inorganic–organic heterojunction was investigated. Favorable band alignment between ZnO, CuS–PVP, and PEDOT:PSS improved conduction, increasing current from 0.3394 to 1.14 mA for D2 (poly‐ethyleneterephthalate/Indium tin oxide/ZnO/PEDOT:PSS/Al) and D1 (poly‐ethyleneterephthalate/Indium tin oxide/ZnO/CuS–PVP/PEDOT:PSS/Al) at a +2 V bias. Transient photo‐responses (J–t) at 0 V bias revealed decreased rise and fall times from 0.382 and 1.154 s to 0.301 and 0.229 s for D2 and D1 devices, respectively. This novel approach provides control over charge carrier transport characteristics at the interface, potentially benefiting self‐powered photo‐detection in optoelectronic devices. This study demonstrates the synthesis of a covellite–polyvinylpyrrolidone nanocomposite matrix using a solution processing approach and the growth of zinc oxide nanorods on an Indium tin oxide coated polyethyleneterephthalate substrate. The study reveals the impact of covellite–polyvinylpyrrolidone on the optoelectronic performances of zinc oxide/poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate), showing enhanced conductivity and improved photo‐response. The findings suggest potential applications in self‐powered photo‐detection, solar cells, and advanced sensors.
Databáze: Supplemental Index