Engineering the Photoresponse of InAs Nanowires.

We report on individual-InAs nanowire optoelectronic devices which can be tailored to exhibit either negative- or positive-photoconductivity (NPC or PPC). The NPC photoresponse time and magnitude is found to be highly tunable by varying the nanowire diameter under controlled growth conditions. Using hysteresis characterisation we decouple the observed photoexcitation-induced hot electron trapping from conventional electric field-induced trapping to gain a fundamental insight into the interface trap states responsible for NPC. Furthermore, we demonstrate surface passivation without chemical etching which both enhances the field-effect mobility of the nanowires by approximately an order of magnitude and effectively eliminates the hot carrier trapping found to be responsible for NPC, thus restoring a positive photoresponse. This opens pathways towards engineering semiconductor nanowires for novel optical-memory and photodetector applications.

Citation

Jack A Alexander-Webber, Catherine Groschner, Abhay A Sagade, Gregory Tainter, Miguel Fernando Gonzalez Zalba, Riccardo Di Pietro, Jennifer Wong-Leung, Hark Hoe Tan, Chennupati Jagadish, Stephan Hofmann, Hannah J Joyce. Engineering the Photoresponse of InAs Nanowires. ACS applied materials & interfaces. 2017 Nov 24

PMID: 29171260

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