Hybrid quantum dot-tin disulfide field-effect transistors with improved photocurrent and spectral responsivity

Authors

Yuan Huang, Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York
Huidong Zang, Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York
Jia -Shiang Chen, Brookhaven National Laboratory
Eli Sutter, University of Nebraska-LincolnFollow
Peter Sutter, University of Nebraska-LincolnFollow
Chang- Yong Nam, Brookhaven National LaboratoryFollow
Mircea Cotlet, Brookhaven National LaboratoryFollow

Document Type

Article

Date of this Version

2016

Citation

APPLIED PHYSICS LETTERS 108, 123502 (2016)

Comments

Copyright 2016 AIP Publishing LLC

Abstract

We report an improved photosensitivity in few-layer tin disulfide (SnS2) field-effect transistors (FETs) following doping with CdSe/ZnS core/shell quantum dots (QDs). The hybrid QD-SnS₂ FET devices achieve more than 500% increase in the photocurrent response compared with the starting SnS₂-only FET device and a spectral responsivity reaching over 650 A/W at 400 nm wavelength. The negligible electrical conductance in a control QD-only FET device suggests that the energy transfer between QDs and SnS₂ is the main mechanism responsible for the sensitization effect, which is consistent with the strong spectral overlap between QD photoluminescence and SnS₂ optical absorption as well as the large nominal donor-acceptor interspacing between QD core and SnS₂. We also find enhanced charge carrier mobility in hybrid QD-SnS₂ FETs which we attribute to a reduced contact Schottky barrier width due to an elevated background charge carrier density.