Structural and optical properties of InxGa1−xAs strained layers grown on GaAs substrates by MOVPE

• Structural and optical properties of InGaAs/GaAs strained structures were studied.
• Reciprocal space mappings in the vicinity of (0 0 4) and (1 1 5) nodes, were performed.
• Strain and indium composition impact on HRXRD, PL and PR responses was quantified.
• Good correlation between the experimental results and the theoretical predictions.

InxGa1−xAs/GaAs pseudomorphic structures were grown by metalorganic vapor phase epitaxy. Reciprocal space mapping were recorded in the vicinity of (0 0 4) and (1 1 5) nodes using high resolution X-ray diffraction (HRXRD) in order to determine strain tensor components, indium compositions and thicknesses of alloys. Near-infrared photoluminescence (PL) was performed at 10 K. The impact of strain on PL response was revealed by peak energy positions and line width. In addition, valence-band splitting (VBS) and the shift of the heavy-hole were measured. Besides, photoreflectance (PR) at room temperature was useful to establish experimentally the dependence of VBS and band energy shifts (E0 and E0+∆0) on elastic strain due to lattice mismatches. Other parameters such as the internal electric-field and the electro-optical energy were determined from Franz–Keldysh oscillations analysis. Good correlation between the results obtained from all investigated techniques and theoretical predictions was confirmed.