BAND-GAP DISCONTINUITY CONTROL FOR INGAAS INGAASP MULTI-QUANTUM-WELL STRUCTURES BY TENSILE-STRAINED BARRIERS/

The changes in InGaAsP conduction- and valence-band edge energies due to tensile strain, have been measured by optical methods at 77 K. The measured increases in the conduction- and valence-band edge energies f or the 0.5% tensile-strained InGaAsP, compared to the unstrained InGaA sP (1.2 mum band-pp wavelength), are 70 and 38 meV, respectively. The experimentally obtained values are in accordance with calculated value s. The results show that the ratio of the conduction- and valence-band discontinuities in InGaAs/InGaAsP multiquantum-well structures can be controlled by the tensile-strained barrier.