Bandgap Restructuring of the Layered Semiconductor Gallium Telluride in Air

Jose J. Fonseca, Sefaattin Tongay, Mehmet Topsakal, Annabel R. Chew, Alan J. Lin, Changhyun Ko, Alexander V. Luce, Alberto Salleo, Junqiao Wu, Oscar D. Dubon

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

Bandgap restructuring of the layered semiconductor gallium telluride in air was investigated. Gallium telluride samples were produced from millimeter thick single crystals by exfoliation using tape or by peeling with a razor blade. Repeating these procedures, flakes with fresh surfaces on both sides were obtained. For samples stored in water, the removal of oxygen from water was performed using a prescribed process. Nitrogen gas was bubbled through deionized water for at least 45 min before samples were placed in it; the bubbling of nitrogen gas was then maintained to achieve the less oxygenated environment. The oxygen content of the water was measured using a dissolved oxygen meter before and after the introduction of samples. The samples were investigated over time by optical absorption and photomodulated refl ectance spectroscopies. Raman and PL spectroscopies were performed using a laser wavelength of 488 nm. First-principles calculations were performed in the framework of DFT. Structural relaxations and phonon calculations were carried out using the well-known Perdew?Burke? Ernzerhof (PBE) exchange-correlation functional including van der Waals corrections.

Original languageEnglish (US)
Pages (from-to)6465-6470
Number of pages6
JournalAdvanced Materials
Volume28
Issue number30
DOIs
StatePublished - 2016
Externally publishedYes

Keywords

  • band structure modification
  • gallium telluride
  • layered semiconductors
  • oxygen chemisorption

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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