First principles exploration of structural, electronic, and optical properties of M2XT2 (M = Hf, Zr; X = C; T = O, F) MXenes for photovoltaic applications.

MXene compounds are promising candidates for energy-related applications because of their tunable electronic and surface properties. In this work, we explore structural, electronic, and optical features of M2XT2 (M = Hf, Zr; X = C; T = O, F) using density functional theory (DFT) within the WIEN2k computational framework. These compounds show non-magnetic behavior and exhibit a hexagonal geometry (space group# 194). Phonon dispersion analysis confirms that these compounds are dynamically stable. Hf2CO2 and Zr2CO2 exhibited indirect bandgaps of 1.1 and 1.12 eV, respectively, classifying them as solar absorber materials. Conversely, Hf2CF2 and Zr2CF2 are semimetals because of the small energy interband overlapping. Their optical properties were explained in terms of optical conductivity, loss parameter, extinction coefficient, refractive index, reflectivity, absorption coefficient, and dielectric function. Our findings indicate that M2XT2 materials are suitable for sustainable energy technologies, including photovoltaic cells and other optoelectronic applications.