Unveiling the Electronic Structure of Pseudotetragonal WO₃ Thin Films

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Tungsten oxide (WO3) is a versatile 5d compound with numerous applications, including flexopiezoelectricity, electrochromism, and battery technology.
• WO3 thin films are promising for stabilizing electronic phases, but their electronic structure is experimentally unexplored, and thermal instability limits applications.

Purpose of the Study:

• To investigate the electronic structure of strained WO3 thin films.
• To stabilize WO3 thin films using tensile strain, creating a pseudotetragonal phase.
• To understand the impact of strain on the electronic properties and thermal stability of WO3.

Main Methods:

• Employing tensile strain to stabilize WO3 thin films.
• Utilizing photoelectron spectroscopy to probe the electronic structure.
• Performing density functional theory calculations for theoretical validation.

Main Results:

• The study successfully stabilized WO3 thin films in a pseudotetragonal phase using tensile strain.
• Significant energy splittings between different orbital manifolds were identified due to atomic distortions.
• The electronic structure and Fermiology of the strained material were experimentally explored.

Conclusions:

• Tensile strain is an effective method to stabilize WO3 thin films and explore their electronic properties.
• Observed orbital splittings and enhanced thermal stability offer pathways for controlling electronic scattering.
• This research paves the way for utilizing WO3 in advanced electronic devices by tuning its electronic behavior.