Competing structures in (In,Ga)Se and (In,Ga)2Se3 semiconductors
Résumé
The electronic structure of four polytypes (β, γ, δ and ε) of hexagonal GaSe and InSe is cal-
culated from first principles, using the WIEN2k and VASP codes and PBEsol prescription for the
exchange-correlation potential, aiming specifically at elucidating the crystallographic parameters
and comparing the energy placement of corresponding competing structures.
Further on, the compounds with different composition of the same constituents, namely the
ordered-vacancies systems Ga2 Se3 and In2Se3, were subject to a similar study, of which the relaxed
crystal structure data for three different phases is reported. Comparison is done with the nomi-
nal wurtzite structure over which the cation vacancies are introduced, and the relaxation pattern
discussed.