Thermal effect on quantum confinement in ZnS0.06Se0.94/Zn0.8Cd0.2Se quantum wells

ZnS0.06Se0.94/Zn0.8Cd0.2Se quantum wells (QW) were studied by temperature-d ependent photoluminescence (PL) measurement. We observed two PL peaks due t o the band-to-band transition in ZnS0.6Se0.94 barrier, E-g(0) = 2.819 eV, a nd the transition of heavy hole to first conduction subband in Zn0.8Cd0.2Se well, E-hhl(0) = 2.545 eV. The relative thermal coefficients of these two constituent materials are quite different, resulting in a temperature-depen dent quantum confinement. The reduction of the quantum confinement at high temperatures induces a leakage of carrier and leads to a quenching of the P L intensity. The activation energy for the PL quench is about 188.4 meV. (C ) 2001 Published by Elsevier Science Ltd.