EXCITONIC TRANSITIONS IN INGAP INALGAP STRAINED QUANTUM-WELLS/

Excitonic transitions in metalorganic vapor phase epitaxially grown In xGa1-xP/In0.48(Al0.7Ga0.3)0.52P strained single quantum-well structure s are characterized using low-temperature photoluminescence and photol uminescence excitation (PLE) spectroscopies. The structures consist of several uncoupled quantum wells with thicknesses between 1.2 and 11.3 nm, and compositions x of 0.48 (nominally lattice matched) and 0.56 ( approximately 0.6% biaxial compressive strain). The photoluminescence spectra exhibit intense peaks over the wavelength range 550-650 nm, wi th linewidths between 7 and 23 meV depending on the well thickness. Th e PLE spectra reveal strong heavy-hole and light-hole transitions, as well as higher-order (n=2) transitions in the thicker wells. The heavy -hole/light-hole splitting shows little dependence on well thickness i n the strained structures, indicating a relatively large conduction ba nd offset of DELTAE(C) is similar to 0.75DELTAE(G).