Surface effects on optical and electrical properties of ZnO nanostructures

Abstract

This article presents a comprehensive review of the current research addressing thesurface effects on physical properties and potential applications of nanostructured ZnO.Studies illustrating the transport, photoluminescence (PL), and photoconductivity propertiesof ZnO with ultrahigh surface-to-volume (S/V) ratio are reviewed first. Secondly, we exam-ine recent studies of the applications of nanostructured ZnO employing the surface effect ongas/chemical sensing, relying on a change of conductivity via electron trapping and detrap-ping process at the surfaces of nanostructures. Finally, we comprehensively review the photo -voltaic (PV) application of ZnO nanostructures. The ultrahigh S/V ratios of nanostructureddevices suggest that studies on the synthesis and PV properties of various nanostructuredZnO for dye-sensitized solar cells (DSSCs) offer great potential for high efficiency and low-cost solar cell solutions. After surveying the current literature on the surface effects on nano -structured ZnO, we conclude this review with personal perspectives on a few surface-relatedissues that remain to be addressed before nanostructured ZnO devices can reach their ulti-mate potential as a new class of industrial appl