Thermally detected optical absorption, reflectance, and photoreflectance of In(As,P)/InP quantum wells grown by gas source molecular beam epitaxy

This work reports an extensive optical study of a series of In(As,P)/InP st rained quantum wells grown by gas source molecular beam epitaxy with variou s thicknesses and compositions. Thermally detected optical absorption, refl ectance, and photoreflectance measurements have been performed in order to determine all the exciton energies. An envelope function model including ba nd nonparabolicity, intervalence band coupling, and also possible group V e lement exchange at the interfaces, is used to interpret the experimental da ta. The fit of the optical transition energies leads to an accurate determi nation of the crucial structural and optical parameters. The arsenic concen tration inside the wells is evaluated and the conduction band offset ratio (Q(c)=0.70) as well as the bowing parameter of In(As,P) (C=0.14 eV) are det ermined. These studies also provide useful information about the nanometer- scale P-As interface mixing. (C) 2000 American Institute of Physics. [S0021 - 8979(00)06220-4].