Preparation of highly (001)-oriented photoactive tungsten diselenide (WSe2) films by an amorphous solid-liquid-crystalline solid (aSLcS) rapid-crystallization process

Farabi Bozheyev, Dennis Friedrich, Man Nie, Mythili Rengachari, Klaus Ellmer

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Highly (001)-textured tungsten diselenide WSe2 thin films have been prepared by a two-step process on quartz glass and TiN metallic back contacts, respectively. At first, X-ray amorphous, selenium-rich WSe2+x films were deposited by reactive magnetron sputtering at room temperature onto a thin metal promoter film (Ni or Pd) and afterwards annealed in an H2Se/Ar atmosphere. X-ray diffraction and scanning electron microscopy show that highly (001)-oriented WSe2 films can be grown, which is caused by the formation of liquid promoter-metal selenide droplets which dissolve tungsten or tungsten selenide at temperatures, higher than the eutectic temperature in the promoter metal-selenium system, followed by oversaturation and eventually crystallization of WSe2 platelets. Time-resolved microwave conductivity measurements show that the films are photoactive. The sum of the carrier mobilities of the best films μe + μh is in the range of 1-7 cm2 V-1 s-1.

Original languageEnglish
Pages (from-to)2013-2019
Number of pages7
JournalPhysica Status Solidi (A) Applications and Materials Science
Volume211
Issue number9
DOIs
Publication statusPublished - Jan 1 2014

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Keywords

  • dichalcogenides
  • magnetron sputtering
  • rapid crystallization
  • WSe

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering
  • Materials Chemistry

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