Extended Short-Wavelength Infrared Photoluminescence and Photocurrent of Nonstoichiometric Silver Telluride Colloidal Nanocrystals

Gahyeon Kim, Dongsun Choi, So Young Eom, Haemin Song, Kwang Seob Jeong

Research output: Contribution to journalArticlepeer-review

Abstract

Demands on nontoxic nanomaterials in the short-wavelength infrared (SWIR) have rapidly grown over the past decade. Here, we present the nonstoichiometric silver chalcogenide nanocrystals of AgxTe (x > 2) and Ag2Te/Ag2S CQDs with a tunable bandgap across the SWIR region. When the atomic percent of the metal and chalcogenide elements are varied, the emission frequency of the excitonic peak is successfully extended to 2.7 μm. Surprisingly, the AgxTe CQD film responds to the SWIR light with a responsivity of 2.1 A/W at 78 K. Also, the Ag2S shell growth over the Ag2Te core enhances not only the emission intensity but also the structural rigidity, preventing crystal morphology deformation under the electron beam. The origin of the enhancement in the emission intensity and air stability of AgxTe and Ag2Te/Ag2S CQDs is carefully investigated by X-ray photoelectron spectroscopy (XPS). The optical properties and infrared photocurrent of AgxTe CQDs will provide new opportunities for solution-based SWIR applications.

Original languageEnglish
Pages (from-to)8073-8079
Number of pages7
JournalNano Letters
Volume21
Issue number19
DOIs
Publication statusPublished - 2021 Oct 13

Keywords

  • AgTe colloidal quantum dot
  • core-shell
  • extended SWIR photocurrent
  • extended SWIR PL
  • nonstoichiometry

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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