First-principles calculations to investigate structural, electronic, elastic and optical properties of radium based cubic fluoro-perovskite materials

Investigation of ultra wide bandgap Flouro-perovskite materials RBeF3 (R K and Li) for smart window applications: A DFT study

“…Negative (-ve) values denote E below the Fermi level E F , or VBM (valence band maximum), and are displayed against the y-axis [ 33 ]. CBM (conduction band minimum) over the E F is indicated by positive (+ve) numbers.…”

“…A high value for B denotes an elevated level of crystal hardness, so it's important to note that LiBeF 3 has a higher value for B than other crystals, suggesting that it is more rigid than the rest of the crystals. Bulk modulus (B) is an indicator of crystal stiffness [ 33 ]. The anisotropy factor, denoted by the letter A, was equivalent to a factor intended for isotropic matter and an amount that is different from an anisotropy factor.…”

Investigation of structural, electronic, mechanical, & optical characteristics of Ra based-cubic hydrides RbRaX3 (X= F and cl) perovskite materials for solar cell applications: First principle study

“…Further, optical properties such as n (ω) is calculated by Equation (10) , L (ω) is calculated by Equation (11), I (ω) is calculated by Equation (12) , and R (ω) is calculated by Equation (13) as follows: [ 42 ]. n(ω) = [ ε 1 (ω)/2 + { ε 2 1 (ω) + ε 2 1 (ω) } 1/2 /2 ] 1/2 L(ω) = − I m ( ε (ω)− 1 ) = ε 2 (ω) / ε 1 (ω) 2 + ε 2 (ω) 2 I(ω) = 2 1/2 ω [{ ε 2 1 (ω) + ε 2 1 (ω) } 1/2 − ε 1(ω) ] 1/2 R(ω) = (n + ik − 1) / (n + ik + 1) …”

A DFT study of structural, electronic, optical, thermal and mechanical properties of cubic perovskite KGeX3 (X = Cl, Br) compound for solar cell applications

“…The sum of electronic states across all energy levels in a material is called the 'Total Density of States' (TDOS). It presents an in-depth analysis of the distribution of electronic states and indicates how many states there are in each energy interval [51][52][53]. Figure 4 demonstrates the TDOS graphs of studied halide perovskites.…”