ABSTRACTIn this work, In0.5Ga0.5P layers were grown by Chemical Beam Epitaxy on GaAs (001) substrates. A set of samples was grown with temperatures kept in the range of 500°C to 560°C with V/III ratio 15. Another set was grown at 560°C with V/II ratio varied in the range 15 to 35. The evolution of ordering as function of growth temperature and V/III ratio was evaluated by photoluminescence measurements at 77K, Transmission Electron Diffraction (TED) and images using Transmission Electron Microscopy (TEM)-Dark Field. A 48meV reduction in the band gap energy was measured by photoluminescence measurements at 77 K when growth temperature was increased. This result is associated to the occurrence of CuPtB ordering in the InGaP layers observed by TED. The TEM-Dark field examination shows that the ordered domains are larger for samples grown at higher temperaturesA small reduction in band gap, from 1.915eV to 1.902eV, occurs when the V/III ratio is increased from 15 to 35. The TED patterns present diffuse scattering for all samples. For those grown with higher V/III ratio, spots are also observed. TEM-dark field images show that the ordered regions become larger, elongated and inclined; some of them exhibit long range ordering
