Solution-Processed Layered Gallium Telluride Thin-Film Photodetectors

Joohoon Kang, Vinod K. Sangwan, Hong Sub Lee, Xiaolong Liu, Mark C. Hersam*

*Corresponding author for this work

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

Using scalable solution processing, layered gallium telluride (GaTe) nanoflake dispersions are produced in surfactant-free, low-boiling-point, water-ethanol cosolvent mixtures. During exfoliation, chemical degradation of the ambient-reactive GaTe crystals is minimized by using deoxygenated solvents in a sealed tip ultrasonication system. The structural and chemical integrity of the solution-processed GaTe nanoflakes is subsequently confirmed with a comprehensive suite of microscopic and spectroscopic analyses. Furthermore, field-effect transistors and phototransistors based on individual solution-processed GaTe nanoflakes show electronic and optoelectronic properties, respectively, that are comparable to micromechanically exfoliated GaTe. Minimal solution-processing residues from the surfactant-free, low-boiling-point cosolvent dispersion medium coupled with the high intrinsic hole doping of GaTe produces the highest electrical conductivity among solution-processed layered nanoflake thin films without post-treatment. Large-area photodetectors based on these electrically percolating thin films of solution-processed GaTe nanoflakes show a positive correlation between responsivity and illumination intensity, with a high photoconversion gain that is explained by a combination of defect-mediated optical processes and photothermal effects. Overall, this study establishes solution-processed layered GaTe nanoflakes as a leading candidate for high-performance, large-area, thin-film photodetectors.

Original languageEnglish (US)
Pages (from-to)3996-4002
Number of pages7
JournalACS Photonics
Volume5
Issue number10
DOIs
StatePublished - Oct 17 2018

Keywords

  • anhydrous
  • gallium telluride
  • liquid phase exfoliation
  • photodetector
  • transistor
  • two-dimensional

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biotechnology
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

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