title: Electrostatic potentials at Cu(In,Ga)Se2 grain boundaries: experiment and simulations.
abstract: In the present Letter, we report on a combined ab initio density functional theory calculation, multislice simulation, and electron holography study, performed on a Σ9 grain boundary (GB) in a CuGaSe2 bicrystal, which exhibits a lower symmetry compared with highly symmetric Σ3 GBs. We find an electrostatic potential well at the Σ9 GB of 0.8 V in depth and 1.3 nm in width, which in comparison with results from Σ3 and random GBs exhibits the trend of increasing potential-well depths with lower symmetry. The presence of this potential well at the Σ9 GB can be explained conclusively by a reduced density of atoms at the GB. Considering experimental limitations in resolution, we demonstrate quantitative agreement of experiment and theory.
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany. sebastian.schmidt@helmholtz-berlin.de
authors.forename: Sebastian S
authors.initials: SS
authors.lastname: Schmidt
authors.forename: Daniel
authors.initials: D
authors.lastname: Abou-Ras
authors.forename: Sascha
authors.initials: S
authors.lastname: Sadewasser
authors.forename: Wanjian
authors.initials: W
authors.lastname: Yin
authors.forename: Chunbao
authors.initials: C
authors.lastname: Feng
authors.forename: Yanfa
authors.initials: Y
authors.lastname: Yan