Thickness-dependent valence-band photoemission from thin InAs and GaAs films - art. no. 195314

With the aim to follow the development of the electronic properties in thin films, angle-resolved photoelectron spectroscopy has been used to investig ate molecular beam epitaxy grown InAs layers on GaAs(111)A and GaAs layers on AlAs(100), lattice mismatch 7.2% and 0.1%, respectively. The results sho w that the bulk electronic structure in the overlayer material is establish ed only in films thicker than 3-4 nm and that the interface region in effec t displays alloylike electronic properties even though the interface is geo metrically abrupt. Comparing computations of strain effects on the electron ic structure in bulk InAs with the experimental data on the InAs cap layers , it was possible to separate the contributions of geometrical strain effec ts, extending 5-6 nm into the overlayer, and the electronic interface effec ts, extending 3-4 nm.