Strain-Induced Hierarchy of Energy Levels in CdS/ZnS Nanocrystals

Phadnis, Chinmay and Sonawane, Kiran G. and Hazarika, Abhijit and Mahamuni, Shailaja (2015) Strain-Induced Hierarchy of Energy Levels in CdS/ZnS Nanocrystals. In: JOURNAL OF PHYSICAL CHEMISTRY C, 119 (42). pp. 24165-24173.

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Abstract

Aside of size and shape, the strain induced by the mismatch of lattice parameters between core and shell in the nanocrystalline regime is an additional degree of freedom to engineer the electron energy levels. Herein, CdS/ZnS core/shell nanocrystals (NCs) with shell thickness up to four monolayers are studied. As a manifestation of strain, the low temperature radiative lifetime measurements indicate a reduction in Stokes shift from 36 meV for CdS to 5 meV for CdS/ZnS with four monolayers of overcoating. Concomitant crossover of S- and P-symmetric hole levels is observed which can be understood in the framework of theoretical calculations predicting flipping the hierarchy of ground hole state by the strain in CdS NCs. Furthermore, a nonmonotonic variation of higher energy levels in strained CdS NCs is discussed.

Item Type:	Journal Article
Publication:	JOURNAL OF PHYSICAL CHEMISTRY C
Publisher:	AMER CHEMICAL SOC
Additional Information:	Copy right for this article belongs to the AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	03 Dec 2015 04:46
Last Modified:	03 Dec 2015 04:46
URI:	http://eprints.iisc.ac.in/id/eprint/52845

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