Modulation spectroscopy study of a strained layer GaAs/GaAsP multiple quantum well structure

摘要: Using contactless electroreflectance (CER) and piezoreflectance at 300 K we have characterized a GaAs/GaAs1−xPx multiple quantum well (MQW) structure, “GaAs” (nominal) GaAsP epilayers grown by chloride transport chemical vapor deposition on GaAs (001) substrates. From detailed lineshape fit to the CER data from determined energies of fundamental band gap hence phosphorous composition. The nominal were found compositions about 2.5–3.2%, result diffusion between growth chambers in reactor. GaAs1−xPx epilayer had x=0.29. For GaAs0.97P0.03/GaAs0.71P0.29MQW comparison experimentally observed number transitions with theoretical envelope function calculation, including effects strain barriers, made it possible evaluate unstrained conduction offset parameter Qc=0.50±0.05. Our value for this is discussed relation other works. Atomic force microscopy was employed investigate surface morphology 230 A top layer MQW addition 2000 epilayer. absence any cross-hatch pattern associated misfit dislocations former concluded that pseudomorphic. On hand exhibited signs relaxation.