STRUCTURAL PHASE TRANSITION, ELASTIC AND ELECTRONIC PROPERTIES OF CuXSe₂(X = In, Ga) CHALCOPYRITE

Abstract

The structural, elastic and electronic properties of chalcopyrite compound CuInSe2 and CuGaSe2 have been investigated using the full-potential linearized muffin-tin orbital method (FP-LMTO) within the frame of density functional theory (DFT). In this approach, the local density approximation is used for the exchange-correlation potential using Perdew–Wang parametrization. The equilibrium lattice parameters, bulk modulus, transition pressure, elastic constants and their related parameters such as Poisson's ratio, Young modulus, shear modulus and Debye temperature were calculated and compared with available experimental and theoretical data. They are in reasonable agreement. In this paper the electronic properties are treated with GGA + U approach, which brings out the important role played by the d-state of noble metal (Cu) and give the correct nature of the energy band gap. Our obtained results show that both compounds exhibit semi-conductor behaviour with direct band gap.

Phase stability and elastic properties of CuGaSe2 under high pressure

“…The bulk modulus from DFT calculations depend on using the correlation functional and equation of state. The calculated result from LDA-PW by fitting to a third-order Vinet equation of state [3] is 84.5 GPa, while the FP-LMTO þLDA result fitting from Birch equation of state [25] is 79.97 GPa, and GGA-PBE (in VASP) result fitting from Murnaghan equation of state in Ref. [12] is 57.7 GPa.…”

“…A study of elastic properties in each stable structure is significant to understand the mechanical properties of CuGaSe 2 under high pressure. We compare the elastic properties at 0 GPa with previous works [3,25] as shown in Table 3. C 11 , C 12 and C 13 from GGA-PBE are lower than other calculations, while C 33 , C 44 and C 66 are in good agreement.…”