LIQUID-PHASE EPITAXIAL-GROWTH AND PHOTOLUMINESCENCE OF MN-DOPED INGAAS WITH INAS-ENRICHED COMPOSITION

Liquid phase epitaxial (LPE) growth was used for the fabrication of ternary In0.97Ga0.03As with a room temperature energy gap of 0.375 eV, corresponding to the fundamental hydrocarbon absorption band at 3.32 mum. The inherent lattice mismatch in the InGaAs/InAs system was found to have little detrimental effect on the quality of epitaxial material with InAs-rich compositions for > 13 mum thick layers. Compositional grading in the material was found to be negligible for the (< 20 mum) range of layer thicknesses investigated in the present work. Optimized LPE growth produced epitaxial InGaAs with quantum efficiency greater than that of the InAs binary substrate, characteristic of high-quality alloy material. The photoluminescence emission intensity was observed to increase with epitaxial layer thickness. This was correlated with the decreased threading dislocation density found in thicker samples. From photoluminecence measurements, the energy gap of undoped In0.97Ga0.03As was measured to be 0.430 eV at 80 K. The presence of an acceptor state with an activation energy of 36 meV was also identified in the spectra of p-type InGaAs, and was associated with intentional manganese doping.