Exploring the candidacy of Mo(1−X) Ax X2 (A = [Cr, Ta], X = S) for photodetection solicitations: showcasing the DFT predictions of the structural, elastic, and optoelectronic properties

Abstract

Previously, most of the theoretical/computational density functional theory (DFT) simulations of transition metal dichalcogenides (TMDs) were used to gain insight into their non-doped structural, elastic, and optoelectronic properties. Although it was shown that most of the TMDs proprieties are relevant giving thereby rise to much more attention due to their promising features with vast potential in many technological applications, it was not clear concerning the stability of these interesting and timely materials. In general, for TMDs the substitutional doping method, which consists of carrier doping by substituting chalcogen or metal sites with impurity atoms, is key for tailoring their physical properties and enabling outstanding stability. In this study, a particular focus will be dedicated to elucidating the stability and the physical properties of Cr and Ta-doped Molybdenum-based TMDs. Since the stability of TMDs depend on the formation energy and occurs on very long timescales, all-DTF and simulations of the physical properties of TMDs are prohibitively costly. However, the inclusion of Cr and Ta in the monolayer MoS2 matrix may pave the way for obtaining excellent stability of TMDs materials and reasonably reduce the computational cost. In this investigation, an illustration of the effect of the Cr and Ta impurities on the overall performance of the monolayer MoS2 matrix will be elucidated. Interestingly, an investigation of Mo(1−x)A(x)X2(A = [Cr, Ta], X = [S]) will be performed starting from the elucidation of the structural properties. It is found that the doped materials are semiconductors within the infrared region, with particular values of the energy gaps. The optical properties findings reveal that Ta–Cr-doped materials are more transparent than those counterparts of Cr and Ta-doped materials. The absorption coefficient spectra, refractive index, reflectivity, and conductivity all reveal good enhancement capability of the doped materials. The computational approach used herein is expected to open the way towards a comprehensive understanding of an efficient application of TMDs doped materials in many ranges of optical applications such as those involved in photodetection technology.