STIMULATED-EMISSION PROCESSES IN ZN1-XCDXSE ZNSE MULTIQUANTUM WELLS/

A stimulated emission effect has been studied in Zn1-xCdxSe/ZnSe (x=0. 3) multiquantum wells (MQWs) with the well width of 7 to 70 angstrom. The luminescence spectrum of the quantum well (QW) exciton at 4.2 K is shifted from the absorption spectrum by 10-12 meV to the lower-energy side. The deviation of the peak energy of the luminescence shows that the excitons in the MQW are inhomogeneously broadened by the monolaye r fluctuation of the QW width. Stimulated emission is observed in the low-energy shoulder of the exciton luminescence band, which shifts to lower energies with increasing excitation intensity. The gain process is explained by the exciton-exciton scattering in the MQWs.