Journal article

Electronic Structure Engineering in ZnSe/CdS Type-II Nanoparticles by Interface Alloying

Klaus Boldt, Kyra N Schwarz, Nicholas Kirkwood, Trevor A Smith, Paul Mulvaney

The Journal of Physical Chemistry C: Energy Conversion and Storage, Optical and Electronic Devices, Interfaces, Nanomaterials, and Hard Matter | American Chemical Society | Published : 2014

Abstract

We report the synthesis and characterization of type-II ZnSe/CdS semiconductor nanocrystals that exhibit strong charge separation, high photoluminescence quantum yields, low optical gain thresholds, and alloyed core–shell interfaces. Shell growth rates and the degree of alloying both depend strongly on the shelling temperature. The core–shell NCs exhibit band edge PL with emission wavelengths spanning the blue to orange region of the electromagnetic spectrum (380–562 nm). Fluorescence quantum yields up to 75% can be obtained by deposition of an additional ZnS layer. Transient absorption spectroscopy reveals that the population of the first two exciton states (1Se–1Sh, 1Se–2Sh) in the type-II..

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University of Melbourne Researchers

Grants

Awarded by ARC


Funding Acknowledgements

The authors thank Dr. Jacek Jasieniak and Prof. Kenneth P. Ghiggino for helpful discussions. K.B. acknowledges the support of the Alexander von Humboldt Foundation through a Feodor Lynen research fellowship. K.N.S. acknowledges scholarship and funding support of the Australian Government through the Australian Renewable Energy Agency (ARENA). Responsibility for the views, information, or advice expressed herein is not accepted by the Australian Government. N.K. thanks the Melbourne Materials Institute for support through an MMI/CSIRO scholarship. T.A.S. acknowledges support from the ARC Centre of Excellence for Coherent X-ray Science. P.M. acknowledges the support of the ARC through DP 130102134.