OPTICAL AND LUMINESCENCE PROPERTIES OF STRESSED LAYERS WITH QUANTUM-WELLS IN GAINASP INP HETEROSTRUCTURES GROWN BY MOS HYDRIDE EPITAXY/

The photoluminescence and photovoltaic response spectra of GaInAsP/InP heterostructures in stressed layers with quantum wells are studied. T he well thickness is varied from 20 to 140 Angstrom and the elastic co mpression strain is varied from 0.5 to 1.5%. A comparison of theoretic al calculations with the photovoltaic response spectra reveals the ene rgy levels in the conduction and valence bands between which optically absorbing transitions of the charge carriers are observed as the thic kness of the quantum well is varied. The transitions with the lowest e nergies are in good agreement with the photoluminescence measurements. Two major mechanisms for broadening of the photoluminescence band are examined: fluctuations in the composition of the solid solution and i n the thickness of the quantum wells. When the quantum wells are thick er than 80 Angstrom, the inhomogeneity in the composition is dominant. For thinner quantum wells, both mechanisms affect the broadening of t he photoluminescence band. (C) 1996 American Institute of Physics.