Skip to main content

Research Repository

Advanced Search

Dual wavelength (ultraviolet and green) photodetectors using solution processed zinc oxide nanoparticles

O'Neill, Mary; Ibrahem, Mohammed A.; Verrelli, Emanuele; Lai, Khue T.; Kyriakou, Georgios; Lee, Adam F.; Isaacs, Mark A.; Cheng, Fei; O’Neill, Mary


Mary O'Neill

Mohammed A. Ibrahem

Profile Image

Dr Emanuele Verrelli
Lecturer in Physics, Director of Postgraduate Researchers, Seminar organiser, First aider

Khue T. Lai

Georgios Kyriakou

Adam F. Lee

Mark A. Isaacs

Fei Cheng

Mary O’Neill


Narrow-band photoconductivity with a spectral width of 0.16 eV is obtained from solution-processed colloidal ZnO nanocrystals beneath the band-edge at 2.25 eV. A new model involving electron transfer from deep defects to discrete shallow donors is introduced to explain the narrow spectrum and the exponential form of the current rise and decay transients. The defects are tentatively assigned to neutral oxygen vacancies. The photocurrent responsivity can be enhanced by storage in air, and this correlates with the formation of carbonate surface species by capture of carbon dioxide during storage. This controllability is exploited to develop a low-cost and scalable photolithographic approach to pixelate photodetectors for applications such as object discrimination, sensing, etc. The spectral response can be spatially patterned so that dual (ultraviolet and green) and single (ultraviolet only) wavelength detecting ZnO pixels can be produced on the same substrate. This presents a new sensor mode with applications in security or full color imaging.


O'Neill, M., Ibrahem, M. A., Verrelli, E., Lai, K. T., Kyriakou, G., Lee, A. F., …O’Neill, M. (2017). Dual wavelength (ultraviolet and green) photodetectors using solution processed zinc oxide nanoparticles. ACS Applied Materials & Interfaces, 9(42), 36971-36979.

Journal Article Type Article
Acceptance Date Sep 26, 2017
Online Publication Date Sep 26, 2017
Publication Date Oct 25, 2017
Deposit Date Dec 8, 2017
Publicly Available Date Sep 27, 2018
Journal ACS Applied Materials & Interfaces
Print ISSN 1944-8244
Electronic ISSN 1944-8252
Publisher American Chemical Society
Peer Reviewed Peer Reviewed
Volume 9
Issue 42
Pages 36971-36979
Keywords Defects; Imaging photodetectors; Persistent photoconductivity; Photolithography; ZnO nanoparticles
Public URL
Publisher URL


Dual Wavelength (ultraviolet And Green) Photodetectors Using Solution Processed Zinc Oxide Nanoparticles (1.3 Mb)

Copyright Statement
This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS applied materials & interfaces, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see DOI: 10.1021/acsami.7b08092

You might also like

Downloadable Citations