Energy transfer in aggregated CuInS2/ZnS core-shell quantum dots deposited as solid films. (20th December 2016)

• Record Type: Journal Article
• Authors: Gardelis, S; Fakis, M; Droseros, N; Georgiadou, D; Travlos, A; Nassiopoulou, A G
• Is Part Of: Journal of physics. Volume 50:Number 3(2017)
• Publication Date: 2016-12-20
• Subjects: photoluminescence -- time resolved photoluminescence -- semiconductor quantum dots -- energy transfer; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/aa4e5d
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: We report on the morphology and optical properties of CuInS2 /ZnS core-shell quantum dots in solid films by means of AFM, SEM, HRTEM, steady state and time-resolved photoluminescence (PL) spectroscopy. The amount of aggregation of the CuInS2 /ZnS QDs was controlled by changing the preparation conditions of the films. A red-shift of the PL spectrum of CuInS2 /ZnS core-shell quantum dots, deposited as solid films on silicon substrates, is observed upon increasing the amount of aggregation. The presence of larger aggregates was found to lead to a larger PL red-shift. Besides, as the degree of aggregation increased, the PL decay became slower. We attribute the observed PL red-shift to energy transfer from the smaller to the larger dots within the aggregates, with the emission being realized via a long decay recombination mechanism (100–200 ns), the origin of which is discussed.