EXCITED-STATE EXCITONS IN STRAINED QUANTUM-WELLS UNDER PRESSURE

We report measurements of the transition energies of the ground and excited state excitons in 100 angstrom quantum wells of In0.15Ga0.85As and In0.18Ga0.82As as a function of hydrostatic pressure by photoconductivity excitation spectroscopy and absorption spectroscopy in a diamond anvil cell. The pressure coefficients of the E1HH1 and E2HH2 transitions agrees well with eight-band k.p theory provided the pressure coefficient of bulk strained InGaAs is given the anomalously low value reponed previously [Wilkinson et al., Phys. Rev. B46, 3113 (1989)]. This result shows that the anomaly is an intrinsic property of the bulk strained crystal and is not associated with defects.