Highly accurate prediction of material optical properties based on density functional theory

Abstract

Theoretical material investigation based on density functional theory (DFT) has been a breakthrough in the last century. Nevertheless, the optical properties calculated by DFT generally show poor agreement with experimental results particularly when the absorption-coefficient (α) spectra in logarithmic scale are compared. In this study, we have established an alternative DFT approach (PHS method) that calculates highly accurate α spectra, which show remarkable agreement with experimental spectra even in logarithmic scale. In the developed method, the optical function estimated from generalized gradient approximation (GGA) using very high-density k mesh is blue-shifted by incorporating the energy-scale correction by a hybrid functional and the amplitude correction by sum rule. Our simple approach enables high-precision prediction of the experimental α spectra of all solar-cell materials (GaAs, InP, CdTe, CuInSe 2 and Cu 2 ZnGeSe 4 ) investigated here. The developed method is superior to conventional GGA, hybrid functional and GW methods and has clear advantages in accuracy and computational cost.

High throughput screening of promising lead-free inorganic halide double perovskites via first-principles calculations

“…The PHS method used in this paper was proposed by Nishiwaki et al 43,53,54 The PHS method uses the absorption coefficient calculated by the PBE functional, and then accurately predicts the absorption coefficient through the energy difference (the band gap difference between the PBE functional and HSE functional) while performing the amplitude correction simultaneously based on the sum rule. The accuracy of the absorption coefficient is determined by the number of K points and the use of functionals.…”

“…To obtain more accurate optical absorption spectra with the lowest computational cost, we adopted the PHS (PBE + HSE06 + sum rule) method. 43 The optical absorption coefficient is then computed as follows:where α is the absorption coefficient, ω is the frequency, c is the speed of light, and ε 1 and ε 2 represent the real part of the dielectric function and the imaginary part of the dielectric function, respectively. ε 2 is calculated in the random phase approximation, and ε 1 is evaluated from ε 2 via the Kramers–Kronig relation.…”

Identification of Potential Optoelectronic Applications for Metal Thiophosphates

“…The carrier effective masses were calculated via an effective mass calculator (EMC) based on the finite difference method . The absorption coefficient spectra were calculated using a high-density k -point mesh (less than 2π × 0.01 Å –1 ) as suggested in ref .…”

Luminescent gold–thallium derivatives with a pyridine-containing 12-membered aza-thioether macrocycle

“…Theoretical calculations represent an invaluable tool in investigating systems as different as optical materials, 52 redox-active compounds, 53,54 or weakly bonded solid-state assemblies. In this context, DFT calculations 55 have been largely adopted to investigate weak interactions such as hydrogen, halogen or chalcogen bonding and metal-metal interactions, and at the…”