Fig. 2: Electronic and phonon properties of WO3 (W atoms in green and O atoms in yellow).
From: The anti-distortive polaron as an alternative mechanism for lattice-mediated charge trapping
a Comparison of the electronic bandgap amplitudes (in eV) and position of the valence band (VB) and conduction band (CB) edges in distinct phases of WO3. b Simple sketch of the valence and conduction bands in the P21/c (left) and P4/nmm (right) phases of WO3, with yellow and green area highlighting respectively the positions of O 2p and W 5d states. The change of hybridization between O 2p and W 5dxy orbitals, yielding the gap opening under atomic distortions from P4/nmm to P21/c, are illustrated from the evolution of wavefunctions valence and conduction states at Γ. c Evolution of the electronic band structure of the P4/nmm phase of WO3 when condensing the \({X}_{5}^{-}\) in-plane antipolar motion, and \({R}_{4}^{+}\) oxygen rotation motions, bringing the system toward the P21/c phase. d Contributions to the polaron atomic distortion of phonon modes at distinct (qx, qy, 0) points of first Brillouin zone of the P21/c phase (using a 6 × 6 × 1 supercell). e Contributions to the polaron atomic distortion of distinct phonon modes from Γ and Γ − C and Γ − Y lines of first Brillouin zone of the P21/c phase. Amplitudes of respective contributions are proportional to the red circles' radii.
