Significant enhancement of photoconductivity in truly two-component and chemically hybridized CdS-poly(N-vinylcarbazole) nanocomposites

Abstract

Ligand exchange leads to efficient triplet energy transfer to CdSe/ZnS Q-dots in a poly(N-vinylcarbazole) matrix nanocomposite

Synthesis and characterization of photorefractive polymer based on chemically hybridized CdS–PVK nanocomposite with a new azo chromophore

“…5, the photocharge generation quantum efficiency as a function of applied electric field at 632.8 nm for the PVK and PVKe10-CdS nanocomposite are presented. It has been reported [10] that CdS particles have little contribution in the absorption of the incident light to produce free carriers directly but are mainly responsible for the increased carrier generation efficiency in PVK when the molar ratio of CdSePVK in the nanocomposites is small. As expected, the results in Fig.…”

“…Nevertheless, a major limitation of organic/inorganic materials is the compatibility between the polymers and semiconductor nanoparticles due to phase separation. The chemically hybridized CdSepoly(N-vinylcarbazole) (PVK) nanocomposites introduced by Wang et al [9,10] could be expected to overcome this weakness, which also exhibit the significant enhancement of photoconductivity as compared to CdS/PVK nanoblends owing to the improved interface quality between CdS and PVK. Besides the photosensitizers, the NLO chromophore plays a key role in PR polymeric materials because it contributes spatially modulated electro-optic and birefringent components to the grating, with the latter being due to the reorientation of the mobile chromophore in the host matrix.…”

Photorefractive effect in a CdS nanoparticles-sensitized polymer composite

“…The PL appears to be from the transition in the carbazole moieties of PVK, and the band gap emission from CdS was not observer. It is because amines (e g, carbazole moiety in this system) are effective complexing agents with the surfaces of CdS clusters, the quenching of the fluorescence of PVK in the PVK/CdS nanocomposite and the absence of band-gap luminescence from CdS result from the charge carrier transport between PVK and CdS nanoparticles [10] . so the photoconductive composites obtained by doping of a host polymer with semiconductor nanoparticles exhibit an increase of the photoconductivity not only due to sensitization of photocharge generation but the presence of nanoparticles may also lead to distinct increase of the effective mobility of charge carriers [11] .…”

Synthesis and photoluminescence spectra of CdS and CdS/ZnO doped PVK nanocomposite films

“…Electrical bistability and negative differential resistance were reported in the currentvoltage characteristics for CdS nanoparticles with different sizes in PVK, when studied in glass/indium tin oxide (ITO)/PVK:CdS/Al system [11]. The improvement in interface quality between CdS and PVK polymers favored fast interfacial carrier transfer giving enhancement of photoconductivity of PVK/CdS nanocomposites [12]. Also the enhanced photoconductivity has been reported for finely dispersed CdS/ZnO core/shell nanoparticles acting as sensitizers in PVK polymer matrix serving as a charge transport medium [13].…”