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

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Ibrahem, M.A., Verrelli, E., Lai, K.T., Kyriakou, G., Lee, A.F., Isaacs, M.A., Cheng, F. and O'Neill, M. ORCID: 0000-0002-0232-5250, 2017. Dual wavelength (ultraviolet and green) photodetectors using solution processed zinc oxide nanoparticles. ACS Applied Materials & Interfaces, 9 (42), pp. 36971-36979. ISSN 1944-8244

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Official URL: http://doi.org/10.1021/acsami.7b08092

Abstract

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 sha llow 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 form ation 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 colour imaging.

Item Type:

Journal article

Publication Title:

ACS Applied Materials & Interfaces

Creators:

Ibrahem, M.A., Verrelli, E., Lai, K.T., Kyriakou, G., Lee, A.F., Isaacs, M.A., Cheng, F. and O'Neill, M.

Publisher:

American Chemical Society

Date:

2017

Volume:

Number: