PBEsol/HSE functional: a promising candidate for vanadium dioxide (B) characterization.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Vanadium dioxide (VO2) exhibits various polymorphs with unique electronic and optical properties.
• Understanding the structural and electronic characteristics of VO2(B) is crucial for its application in smart materials.
• Previous studies may have limitations in accurately predicting the band gap and dynamic stability of VO2(B).

Purpose of the Study:

• To comprehensively investigate the structural, electronic, optical, and vibrational properties of the VO2(B) polymorph using DFT.
• To evaluate the suitability of different DFT functionals for accurately modeling VO2(B).
• To explore the potential applications of VO2(B) nanostructures in optoelectronics.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Generalized Gradient Approximation (GGA)/PBEsol and hybrid HSE functionals were utilized for electronic structure calculations.
• Phonon band structure, Raman spectra, cohesive energy, and optical properties were computed.

Main Results:

• Eight computed Raman modes were assigned to the VO2(B) structure, matching experimental data.
• Phonon dispersion curves revealed negative frequencies, indicating dynamic instability of VO2(B).
• The PBEsol functional predicted a band gap of 0.26 eV, while HSE yielded 0.67 eV, with optical conductivity in the infrared region.

Conclusions:

• The combination of GGA/PBEsol and HSE functionals is recommended for accurate prediction of VO2(B) properties.
• VO2(B) nanostructures show promise for infrared (IR) photodetectors and smart windows due to their semiconductor and optical characteristics.
• VO2(B) is a versatile material with potential for continued advancements in electronics and optoelectronics.