Amorphous WO3-x thin films with color characteristics tuned by the oxygen vacancies created during reactive DC sputtering

• 作者: C.Guillén J.Herrero
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2021,（19）
• 页码范围: 223-228
• 页数: 6页
• 语种: 英文

摘要

Tungsten oxides are interesting for a variety of applications due to their versatile optoelectronic charac-teristics,which can be tuned changing the composition and/or the crystalline structure.Coloration due to sub-bandgap absorption is often achieved by ion intercalation or doping in WO3:M films(with M=H+,Li+,Na+,etc.introducing extra electrons),but a more direct way is creating charged oxygen vacancies(Vo+and/or Vo2+)in sub-stoichiometric WO3-x forms.Here,amorphous WO3-x thin films are obtained by reactive DC sputtering of a pure W target,on unheated glass substrates,changing the oxygen to argon pressures ratio.The control of intrinsic defects(oxygen vacancies and tungsten valence states)by the oxy-gen partial pressure allows tuning the morphology,sub-bandgap absorption and carrier density in these WO3-x films,as it is proven by Raman spectroscopy,atomic force microscopy,optical spectrophotometry and Hall effect measurements.