Reconstruction and energetics of the polar (112) and (112)over-bar versus the nonpolar (220) surfaces of CuInSe2 -: art. no. 081402

First-principles total-energy calculation reveals a number of (112) and ((1) over bar(1) over bar(1) over bar) surfaced structures stable at different atomic chemical potentials. All of the stable structures are charge compensated, thus semiconducting, either by cation-on-cation antisites, cation vacancies, Se adatoms, or by Se addimers. This structural richness raises the possibility for engineering CuInSe2/Cu(In1-xGax)Se-2 material properties by surface control during. the growth. Them experimentally observed puzzling spontaneous decomposition of the (220)/(204) surfaces into (112) and ((1) over bar(1) over bar(2) over bar) is also confirmed by calculating individual surface energies.