Structural, electronic and optical calculations of Cu(In,Ga)Se₂ ternary chalcopyrites

Abstract

In this work, we have investigated the structural, electronic and optical properties of the ternary I -III -VI 2 chalcopyrite semiconductors ABX 2 (A = Cu, B = In, Ga, X = Se) by means of a first-principles densityfunctional total-energy calculation with the local-density approximation (LDA), using the all-electron full-potential linear-augmented plane-wave method (FP-LAPW). The equilibrium lattice constants and the bulk moduli (a, c, c/a, u and B 0 ) are compared with other theoretical calculations. The energy gap at ambient pressure is found to be direct and the nature of the gap crucially depends on the manner in which the d electrons of the A atoms are treated. We have also reported the optical properties of two chalcopyrite semiconductors CuInSe 2 and CuGaSe 2 . Results on complex dielectric functions, refractive indices n, extinction coefficients k, and normal-incidence reflectivity R in the two crystals are given and compared with earlier data where available. We analyze in detail the structures of the dielectric function observed in the studied energy region.

Generalized gradient calculations of structural, electronic and optical properties of MgxCd1−xO oxides

“…Equation for the imaginary part of the frequency dependent dielectric function ε 2 (ω) for cubic structures is given by Belhadj et al [23]:…”

Physical, photoelectrochemical properties of CuIn3Se5 and relevance for hydrogen production

“…Recently, the authors reported the physical properties of CuInSe 2 and its feasibility for hydrogen photocathode [7]. In extension, we present the work relative to CuIn 3 Se 5 which is usually n-type and both VB and CB are associated with Se: 4p orbital [8]. With a gap (Eg) of w1.2 eV [9], near to the optimal value required for terrestrial applications and the foregoing features, CuIn 3 Se 5 appears attractive for the solar energy conversion.…”

Photoelectrochemical hydrogen-evolution over p-type chalcopyrite CuInSe2

“…With an optical gap (Eg) averaging 1 eV [10] close to the optimal value required for terrestrial applications and the foregoing characteristics, CuInSe 2 (CISe) looks like promising one for photovoltaic cells whether liquid [11] or solid junctions [12]. CISe can be made p-type by copper deficiency and both VB and CB are associated mainly with Se: 4p orbital [13]. Photoelectrons in CB have enough negative potential to reduce water into gaseous H 2 even in strongly basic solutions.…”