Photovoltaic spectroscopy of exciton structures in Zn1-xCdxSe/ZnSe multiple quantum wells

Exciton transitions in photovoltaic spectra of strained-layer multiple-quantum-well samples of Zn1-xCdxSe/ZnSe grown by molecular-beam epitaxy were observed up to room temperature. Quantum level energies were calculated by means of the envelope-function method including strain, Great care was taken in order to evaluate the band offsets, the band-gap dependence on temperature and alloy concentration, as well as the quantum confinement enhancement of the exciton binding energies. Very good agreement between experimental and calculated values of the exciton energy position was found in the 80-300 K temperature range. Calculated binding energies as high as 35-40 meV account for the occurrence of the exciton structures up to 300 K. (C) 1996 American Institute of Physics.