A difference method with semi-analytical approach for achieving accuracy in optical gaps of 2D materials using exciton model in fractional space

Abstract

A semi-analytical approach for the difference method using numerically calculated G0W0 band gaps and analytically calculated exciton binding energies based on the fractional Coulomb potential model is proposed to calculate optical gaps of 46 2D materials ranging from ultra-violet to infrared region. The suggested methodology is compared with difference methods of a similar hybrid approach, utilizing conventional exciton models based on Wannier–Mott theory to achieve a significant reduction in the average relative mean square error of optical gaps, up to one-third, benchmarked with a fully numerical approach, employing G0W0 band gaps and the state-of-the-art Bethe–Salpeter equation for binding energy calculation.

Capturing of non-hydrogenic Rydberg series of exciton binding energy in two-dimensional mono-layer WS2 using a modified Coulomb potential in fractional space

“…In this work, the proposed two-step method based on FCP model contributes not only towards analytically calculating the entire excitonic series, demonstrated in mono-layer WS 2 , but in addition, contribute towards achieving comparatively higher accuracy in comparison to existing analytical approaches. In future, the proposed two-step method based on the strained versions of the FCP model [40] and for varying layer thicknesses, can be potentially extended to mono-layer WS 2 and other 2D materials [41] for studying excitonic Rydberg series with potential applications in strain engineered photonic applications. ).…”

Theoretical investigation on harvesting thermal energy beyond the visible spectrum in Ta-doped monolayer MoS2

“…[1][2][3] This quest for innovative energy harvesting approaches has spurred theoretical investigation of nanoscale 2D materials based on first principles calculations, characterized by unique combinations of electrical, optical, mechanical, and thermal properties. [4][5][6][7][8][9] Among these materials, transition metal dichalcogenides (TMDC) stand out as a distinctive group, defined by a general form MX 2 , where M represents a transition metal, paired with a chalcogen X. Molybdenum disulphide (MoS 2 ), a member of the TMDC family, has garnered significant attention owing to its exceptional optical, electronic, thermal, and mechanical properties. 10 The monolayer configuration of MoS 2 is recognized as a semiconductor material having a direct band gap, providing the advantage of band gap engineering for potential thermal energy harvesting within and beyond the visible regime.…”