Disorder-induced Raman scattering of In1−xGaxP in the transverse acoustic phonon region

Raman scattering measurements have been performed on In_1?xGa_xP (0.62?x?1) over the entire frequency range of first and second order scattering. Besides the already known disorder activated band between the LO(Γ) and TO(Γ) modes a new disorder activated band is found in the region of transverse acoustic phonons around 87 cm^-1. The position of the new band shifts only slightly with composition while its strength and line-shape change.     

Outdiffusion of impurities from GaP substrate material by means of postgrowth annealing

The present work is concerned with a reduction procedure for impurities in GaP substrate slices. Bý annealing of GaP in contact with high purity gallium the concentration of definite impurities is reduced. Heat treatment of GaP under phosphorus pressure introduces another efficient extraction mechanism which is based on phosphosilicate glass gettering and well known in silicon technology.

     

Die Konzentrationsabhängigkeit des Brechungsindex von Ga(PAs)- und (GaIn)P-Mischkristallen

In the two systems of mixed crystals Ga_xPAs_1–x and Ga_xIn_1–xP the refraction index — using the wavelength of the green Hg line (λ = 5461 Å) — is determined ellipsometrically in dependence on the mole fraction x. The nonlinearity parameter c_n of this dependence is compared with that estimated theoretically by the use of PENNS model.