Green synthesis of CuInS2/ZnS core-shell quantum dots by facile solvothermal route with enhanced optical properties. (March 2018)

• Record Type: Journal Article
• Authors: Jindal, Shikha; Giripunje, Sushama M.; Kondawar, Subhash B.; Koinkar, Pankaj
• Is Part Of: Journal of physics and chemistry of solids. Volume 114(2018)
• Page Start: 163
• Page End: 172
• Publication Date: 2018-03
• Subjects: Copper indium sulphide -- Core-shell -- Quantum dots -- Ultra-violet photoelectron spectroscopy (UPS) -- Photoluminescence; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2017.11.026
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: We report an eco-friendly green synthesis of highly luminescent CuInS2 /ZnS core-shell quantum dots (QDs) with average particle size ∼ 3.9 nm via solvothermal process. The present study embodies the intensification of CuInS2 /ZnS QDs properties by the shell growth on the CuInS2 QDs. The as-prepared CuInS2 core and CuInS2 /ZnS core-shell QDs have been characterized using a range of optical and structural techniques. By adopting a low temperature growth of CuInS2 core and high temperature growth of CuInS2 /ZnS core-shell growth, the tuning of absorption and photoluminescence emission spectra were observed. Optical absorption and photoluminescence spectroscopy probe the effect of ZnS passivation on the electronic structure of the CuInS2 dots. In addition, QDs have been scrutinized using ultra violet photoelectron spectroscopy (UPS) to explore their electronic band structure. The band level positions of CuInS2 and CuInS2 /ZnS QDs suffices the demand of non-toxic acceptor material for electronic devices. The variation in electronic energy levels of CuInS2 core with the coating of wide band gap ZnS shell influence the removal of trap assisted recombination on the surface of the core. QDs exhibited tunable emission from red to orange region. These studies reveal the feasibility of QDs in photovoltaic and light emitting diodes. Highlights: CuInS2 core and CuInS2 /ZnS core-shell QDs were synthesized by solvothermal method. UPS spectrum was recorded to analyze the electronic energy levels of QDs. CIE chromaticity coordinates illustrate the red and orange region. Optical studies represent the intensification of band gap and the elimination of recombination states in core-shell QDs.