A Transmission Electron Microscopy (TEM), Photoluminescence (PL) and Photoluminescence Excitation Spectroscopy (PLE) investigation has been conducted on Ga0.52In0.48P epilayers grown on (001) GaAs substrates by Gas-Source Molecular Beam Epitaxy.For Ga0.52In0.48P epilayers grown on exact (001) GaAs substrates, increasing the growth temperature from 480°C to 535°C increased the antiphase domain plate thickness, t, from 7.3±0.4 to 17.4±0.9 Å, and decreased the long range order parameter, n, from 0.32 to 0.18±0.1. For epilayers grown at 530°C, on GaAs(001) substrates off-cut 0°, 7°, 10° and 15° towards A, increasing the substrate misorientation from 0° to 15° decreased the antiphase domain plate thickness, from 12.3±0.6 to 6.0±0.3 Å. The long range order parameter also decreased from 0.19 to 0.10±0.01.
The band gap energies of these samples, grown by GS-MBE, were close to those reported for fully disordered Ga0.52In0.48P epilayers grown by MOCVD at ∼760°C. This shows that GSMBE is also a good technique to grow GaInP for high band gap optical data storage applications and at lower growth temperatures. The optimum growth conditions in this study were at a growth temperature of 530°C on (001) GaAs substrate with 15° off-cut towards A.