Interfacial charge carrier dynamics of type-II semiconductor nanoheterostructures

Authors: Yi-Fang Lin, Yung-Jung Hsu

Abstract:
Semiconductor nanoheterostructures with type-II band offset have exhibited unique optoelectronic properties that are beneficial to photoconversion applications. Debatable arguments however exist in the literature for interpreting the most enhanced photocatalytic performance of type-II semiconductor nanoheterostructures when an optimal content of the constituents is employed. In this work, time-resolved photoluminescence is used to investigate the interfacial charge carrier dynamics for CdSnO₃-decoratedCdSnanowires, aprototype type-IInanoheterostructures system, withvaryingCdSnO₃ contents. Our results show thatthe CdSnO₃ content of 2.5 at% rendered CdS–CdSnO₃ NWs the most significant charge carrier separation, above which electron–hole recombination across CdS/CdSnO₃ interface mediated carrier transfer to compromise the overall charge separation efficiency. The carrier dynamics results are in good accordance with that of photoconversion performance evaluation in dye photodegradation, which assists in resolving the very critical but still controversial issue as to the factors causing the depressed photocatalytic efficiency of type-II nanoheterostructures when the constituent content exceeds the optimal value.

Keywords:
Type-II semiconductor nanoheterostructures
Charge separation
Photoconversion
Photocatalysis
CdS nanowires

Published in: Applied Catalysis B: Environmental (Volumes 130–131, Pages 1-336, 7 February 2013)

Publisher: Elsevier  

ISSN Information: 0926-3373

Interfacial charge carrier dynamics of type-II semiconductor nanoheterostructures

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