Improved sensitization of zinc oxide nanorods by cadmium telluride quantum dots through charge induced hydrophilic surface generation
2014 (English)In: Journal of Nanomaterials, ISSN 1687-4110, E-ISSN 1687-4129, Vol. 2014, 919163Article in journal (Refereed) Published
This paper reports on UV-mediated enhancement in the sensitization of semiconductor quantum dots (QDs) on zinc oxide (ZnO) nanorods, improving the charge transfer efficiency across the QD-ZnO interface. The improvement was primarily due to the reduction in the interfacial resistance achieved via the incorporation of UV light induced surface defects on zinc oxide nanorods. The photoinduced defects were characterized by XPS, FTIR, and water contact angle measurements, which demonstrated an increase in the surface defects (oxygen vacancies) in the ZnO crystal, leading to an increase in the active sites available for the QD attachment. As a proof of concept, a model cadmium telluride (CdTe) QD solar cell was fabricated using the defect engineered ZnO photoelectrodes, which showed ∼10% increase in photovoltage and ∼66% improvement in the photocurrent compared to the defect-free photoelectrodes. The improvement in the photocurrent was mainly attributed to the enhancement in the charge transfer efficiency across the defect rich QD-ZnO interface, which was indicated by the higher quenching of the CdTe QD photoluminescence upon sensitization.
Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2014. Vol. 2014, 919163
IdentifiersURN: urn:nbn:se:kth:diva-175172DOI: 10.1155/2014/919163ISI: 000346710300001ScopusID: 2-s2.0-84919754523OAI: oai:DiVA.org:kth-175172DiVA: diva2:914294
QC 201603292016-03-232015-10-102016-03-29Bibliographically approved