The influence of initial stoichiometry on the mechanism of photochromism of molybdenum oxide amorphous films

Mehdi Rouhani, Jonathan Hobley, Gomathy Sandhya Subramanian, In Yee Phang, Yong Lim Foo, Sergey Gorelik

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)

Abstract

We investigate the role of oxygen vacancies in photochromism of molybdenum oxide amorphous films. MoO3-x films with a wide range of initial stoichiometries are deposited using R.F. unbalanced magnetron sputtering. The evolution of visible light absorption in conjunction with Raman spectra for these films is studied in detail during the course of UV-irradiation to correlate the color change to the Mo6+ to Mo5+ conversion. For films which have an initially more complete stoichiometry, and hence lower oxygen vacancy concentration, the color change fully correlates with conversion of Mo6+ to Mo5+. This behavior is consistent with the group of models of photochromism of transition metal oxides which disregard the presence of oxygen vacancies in the films. However, coloration of the films with initially greater deviation from complete stoichiometry, and hence higher oxygen vacancy concentration, is not accompanied by any significant conversion of Mo6+ to Mo5+. This behavior is consistent with the group of models of photochromism of transition metal oxides which rely on the presence of oxygen vacancies. Overall, the reported results demonstrate the importance of the initial stoichiometry in the photochromism of MoO 3-x amorphous films, particularly in the initial stages of UV-irradiation.

Original languageEnglish
Pages (from-to)26-35
Number of pages10
JournalSolar Energy Materials and Solar Cells
Volume126
DOIs
Publication statusPublished - 2014 Jul

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films

Fingerprint Dive into the research topics of 'The influence of initial stoichiometry on the mechanism of photochromism of molybdenum oxide amorphous films'. Together they form a unique fingerprint.

Cite this