Ultra-high negative infrared photoconductance in highly As-doped germanium nanowires induced by hot electron trapping

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John, John Wellington
Dhyani, Veerendra
Georgiev, Yordan M.
Gangnaik, Anushka S.
Biswas, Subhajit
Holmes, Justin D.
Das, Amit K.
Ray, Samit K.
Das, Samaresh
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American Chemical Society
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Here, we report the observation of negative photoconductance (NPC) effect in highly arsenic-doped germanium nanowires (Ge NWs) for the infrared light. NPC was studied by light-assisted Kelvin probe force microscopy, which shows the depletion of carriers in n-Ge NWs in the presence of infrared light. The trapping of photocarriers leads to high recombination of carriers in the presence of light, which is dominant in the n-type devices. Furthermore, a carrier trapping model was used to investigate the trapping and detrapping phenomena and it was observed that the NPC in n-Ge occurred, because of the fast trapping of mobile charge carriers by interfacial states. The performance of n-type devices was compared with p-type NW detectors, which shows the conventional positive photoconductive behavior with high gain of 104. The observed results can be used to study the application of Ge NWs for various optoelectronic applications involving light tunable memory device applications.
Negative photoconductivity , Infrared detection , Hot electron trapping , Germanium nanowire , Diameter-dependent photoconductance
John, J. W., Dhyani, V., Georgiev, Y. M., Gangnaik, A. S., Biswas, S., Holmes, J. D., Das, A. K., Ray, S. K. and Das, S. (2020) 'Ultrahigh Negative Infrared Photoconductance in Highly As-Doped Germanium Nanowires Induced by Hot Electron Trapping', ACS Applied Electronic Materials, 2(7), pp. 1934-1942. doi: 10.1021/acsaelm.0c00245
© 2020 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Electronic Materials, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/full/10.1021/acsaelm.0c00245