Accurate Ab Initio Calculations on Various PV-Based Materials: Which Functional to Be Used?

Abstract

Herein we report a thorough ab initio investigation targeting the optical and electronic properties of 14 binary, ternary, and quaternary compounds (CuInSe2, CuGaSe2, ZnO, ZnS, CuAlSe2, CuInS2, AgInSe2, CuGaS2, AgAlSe2, AgGaSe2, CdIn2S4, Cu2SnZnSe4 (CZTSe), CdS, and α-SiO2 (quartz)) and 1 elemental solid: C (diamond). To perform the present benchmark, different classes of functionals have been chosen in order to sample modern computational methods (e.g., GGA, global hybrids PBE0 and B3LYP, screened hybrid functional HSE, and many-body methods). Our results demonstrate that the PBE-GGA functional reproduces the structure well but is unable to predict optoelectronic properties. However, B3LYP is the worst performing functional for reproducing the structure but, astonishingly, provides accurate band gaps. PBE0 and HSE usually overestimate and underestimate band gaps, respectively. Single-shot many-body calculations (G0W0) were tested on top of the PBE structure and density for several compounds.

Selected Machine Learning of HOMO-LUMO gaps with Improved Data-Efficiency

“…These MO energies are intimately related to chemical reactions, polarizability, the optical gap and excitation energies. Their prediction often plays an important role for design decisions in the development of technological applications such as synthesis planning, electrochromic devices, light-emission diodes or photovoltaic solar panels [43][44][45][46][47][48]. Interestingly, the generation of accurate QML models of frontier orbital eigenvalues proves more difficult than for other quantum properties-even when using molecular training sets of considerable size.…”

Point Defects Modeling Explains Multiple Sulfur Species in Sulfur-Doped Na4(Al3Si3O12)Cl Sodalite

“…In our study, the computed bandgap in GGA is 4.75 eV. Using a more refined model (HSE06), which is known to better reproduce the electronic structure, the bandgap becomes 6.65 eV …”

“…Using a more refined model (HSE06), which is known to better reproduce the electronic structure, the bandgap becomes 6.65 eV. 25 The electrostatic potential is shifted by an unknown value after the introduction of a charge in the cell. 26,27 To recalibrate the charged cells energies, the DFE is corrected by the averaged difference between the potential felt by the atoms far from the defect V D,q r and the potential in the ideal cell V host r weighted by the defect charge.…”

First-principles calculations to identify key native point defects in Sr4Al14O25

“…We found E g (PBE0@SCAN) = 6.37 eV, not far from already reported WC1PBE hybrid results 40 and in line with the work of some of us which predicted more reliable large band gaps with the PBE0 approach. 43 Thus, this PBE0 result will be considered hereafter to readjust calculations carried out with the SCAN functional.…”