Spectroscopic monitoring of the evolution of size and structural defects in kinetic growth of CdSe quantum dots. (2019)

• Record Type: Journal Article
• Authors: Kushavah, Dushyant; Mohapatra, P.K.; Ghosh, Pintu; Vasa, P.; Bahadur, D.; B.P.Singh,
• Is Part Of: Materials today. Volume 9:Part 2(2019)
• Page Start: 237
• Page End: 246
• Publication Date: 2019
• Subjects: CdSe Quantum Dots -- Exciton-phonon coupling -- Temperature dependent photoluminescence -- Thermal escape; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2019.02.155
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: We report here on the exciton- phonon coupling and role of trap states formed at the interface of structural dislocations in CdSe quantum dots (QDs) synthesized by kinetic growth method. Even though non-luminescing, our studies recognize their signatures in the temperature dependent photoluminescence characteristics of lowest QD excitonic state and have some useful implications for structural quality of thus synthesized QDs. We have explained the observed temperature dependence of PL intensity in terms of a simple model taking account of different radiative and nonradiative recombination processes as well as carrier trapping/detrapping and determined the depth of potential well formed due to such long range defects. Our studies indicate the presence of such defect states only in QD samples size sorted by aliquoting at intermediate intervals during the reaction and do not appear when the reaction proceeds uninterrupted.