Composition at the CuInSe2 ZnO interface copper depletion induced by diethyl zinc

Abstract The interface formation between epitaxial CuInSe2 112 films and ZnO deposited by metal organic MBE is investigated by photoelectron spectroscopy. Reaction of diethyl zinc with CuInSe2 leads to the formation of an intrinsic ZnSe layer and copper depletion of the interface. This is associated with Zn doping of the chalcopyrite surface and a Fermi level shift towards the conduction band. The implications on the band alignment are discussed

Photoelectron spectromicroscopy at chalcopyrite films

CuInSe2 films were prepared by MBE on GaAs 111 A substrates. ZnSe and ZnO are subsequently deposited in situ by MOMBE. Interface parameters like band offsets and morphology are studied by X ray photoelectron spectroscopy XPS and Low energy electron diffraction LEED . Spectroscopic XPEEM X ray Photo electron emission microscopy at the U49 2 PGM2 beamline at BESSY was used to investigate the lateral homogenity of the interface. After annealing in situ a lateral inhomogenious In diffusion is observed into the ZnSe ZnO interfac