Photoluminescence quenching and electron transfer in CuInS₂/ZnS core/shell quantum dot and FePt nanoparticle blend films

Abstract

The photoluminescence (PL) quenching of CuInS2/ZnS quantum dots (QDs) in blend films with FePt magnetic nanoparticles (MNs) was studied by steady-state and time-resolved PL spectroscopy.

Light Emission Mechanisms in CuInS2 Quantum Dots Evaluated by Spectral Electrochemistry

“…Our overall assessment is that the stoichiometric samples are more strongly influenced by nonradiative processes involving intragap states compared to Cu-deficient samples. This might explain a commonly observed trend that moderate levels of Cu deficiency lead to improved PL efficiency. − The high sensitivity of both Cu 1+ and Cu 2+ emission channels to electron trapping is also consistent with previous transient absorption and pump–dump–probe spectroscopy studies. , …”

Room temperature synthesis of CuInS2 nanocrystals

“…The rst peak at 20 2q stems from the capping agent oleylamine 39 and all the other peaks can be ascribed to chalcopyrite CuInS 2 and match well with the reference pattern for tetragonal CuInS 2 (PDF 01-75-0208). The distinct diffraction peaks, which are also comparable to others reported for CuInS 2 nanoparticles prepared at higher temperatures, 31,[39][40][41][42] indicate a good crystallization of the nanoparticles even at room temperature. From the broadening of the peaks and using Scherrer equation, a primary crystallite size of 2-3 nm is estimated.…”

Controlled Photoinduced Electron Transfer from InP/ZnS Quantum Dots through Cu Doping: A New Prototype for the Visible-Light Photocatalytic Hydrogen Evolution Reaction

“…Accordingly, η PET can be roughly described as η PET = K ET /(K ET + K TR ). 34 To obtain a direct comparison of K ET and K TR for the undoped and Cu-doped InP/ZnS QD samples, we plotted the K ET and K TR values for the InP/ZnS QD and InP/Cu:ZnS QD samples with various ZnS shell thickness in the present of 40 μM BQ, as represented in Figure 3c (see also Figure S8 for the QD samples in the present of 20 μM BQ). The K ET values of the InP/Cu:ZnS QD samples slightly decreased compared with those of the InP/ZnS QD samples, presumably because photoexcited electrons in the InP/Cu:ZnS QDs is scattered by the extra holes in the p-type Cu doped ZnS shell layers before escaping from the QDs.…”

“…In the QD-BQ system, the photoexcited electrons in the QDs can decay by radiative/nonradiative relaxation pathways or transfer to BQ, and the PET efficiency ( η PET ) from QD to BQ is governed by the rate of electron transfer ( K ET ) and the rate of competing total radiative/nonradiative relaxation pathways ( K TR ). Accordingly, η PET can be roughly described as η PET = K ET /( K ET + K TR ) . To obtain a direct comparison of K ET and K TR for the undoped and Cu-doped InP/ZnS QD samples, we plotted the K ET and K TR values for the InP/ZnS QD and InP/Cu:ZnS QD samples with various ZnS shell thickness in the present of 40 μM BQ, as represented in Figure c (see also Figure S8 for the QD samples in the present of 20 μM BQ).…”