: Borgwarth, K.; Sulima, O.V.; Wettling, W.; Schetter, C.; Bett, A.W.

Abstract
GaAs and AlGaAs layers on (100) Si substrates have been grown by a combination of LPE and MBE. For the first time planar LPE growth without any cracks and dissolution defects on GaAs-coated Si substrate is reported. The layers were characterized by the X-ray rocking curve method. FWHM values of the (400) diffraction peak of the GaAs layer as low as 160 arcs were measured. This corresponds to a dislocation density of less than 10high7 cmhighminus2. It is shown that thermal cycle annealing is a powerful method to increase crystal quality of the GaAs-on-silicon structure, especially for thin GaAs layers (according 1 Mym). A 5-layer AlGaAs/GaAs heteroface solar cell structure was grown by low-temperature LPE on MBE GaAs-coated Si substrates.