Tailoring the properties of Ti3C2 MXenes via transition metal doping for RRAM applications: Using ab-initio calculation

Abstract

Experts consider MXene as a highly sophisticated material that can be utilized in creating effective optoelectronic gadgets due to its exceptional physical properties. Here, the theoretical aspects of the structural, phonon, thermodynamic stability, mechanical, electronic and optical properties of MXenes are computed, serving as a roadmap for scientists for developing high performance MXene based devices. The Plane Wave Augmented (PAW) method is employed within the VASP code framework to investigate the physical properties of pure MXene Ti₃C₂ and doped MXenes Ti₂XC₂, (X = Ni, Fe, Mn, and Co) yielding Ti₂NiC₂, Ti₂FeC₂, Ti₂MnC₂ and Ti₂CoC₂. The results of structural properties show that if the size of dopant atom is greater than Ti atom in Ti₃C₂, then lattice constant for that sample increases. The energy difference between spin polarized and non-spin polarized configurations, their binding energies and phonon properties are also calculated. According to the results of electronic properties, Ti₃C₂ and Ti₂NiC₂ show metallic nature while remaining samples show semiconducting behavior: Ti₂FeC₂ has bandgap of 0.21 eV, Ti₂MnC₂ has bandgap of 0.1eV and Ti₂CoC₂ shows bandgap of 0.23eV. The mechanical stability of pristine and doped MXenes is also tested using the Born Stability criteria. From Phonon symmetry points and Born stability criteria, it is evidenced that all the considered MXenes are mechanically stable. According to the results of optical properties, all MXene samples, particularly Ti₂NiC₂ has high absorption rate and low values of Loss function in the infrared region, thus appearing to be particularly appealing for optoelectronic applications, particularly RRAM devices.