OPTICAL-PROPERTIES OF CDTE-CD0.90MN0.10TE MULTIPLE QUANTUM-WELL STRUCTURES GROWN BY PULSED LASER EVAPORATION AND EPITAXY

Low-temperature photoluminescence, photoluminescence excitation and Raman spectroscopy measurements of CdTe-Cd0.90Mn0.10Te multiple quantum well (MQW) structures grown by pulsed laser evaporation and epitaxy (PLEE) on (001) Cd1-xZnxTe substrates are carried out. The samples are grown from fluxes of Cd-Te and Cd-Mn-Te provided by ablation of solid CdTe and Cd0.93Mn0.07 Te targets with Nd:YAG and excimer XeCl lasers, respectively. The excitonic lines corresponding to the quantum well E1-HH1 transition are investigated. Comparison between the observed PL excitonic emissions and calculated energy levels using a Kronig-Penney model with the well width as a fitting parameter allowed us to determine the "optical" well widths of the samples and to compare them with those determined from secondary ions mass spectroscopy in-depth profiles. Raman spectra for non-resonance excitation at 501.7 nm are dominated by the CdTe-like longitudinal optical (LO) modes at 166 cm-1 and MnTe-like LO modes at 194 cm-1 from the Cd0.90Mn0.10Te barriers. Under resonance conditions, with excitation at 476.5 nm the CdTe LO, 2LO and 3LO modes from the wells near 170, 340 and 510 cm-1 dominate the spectra. The results clearly indicate that the PLEE-grown MQWs have the characteristics of the best currently available material.