ALE growth and optical characterization of ZnSe/ZnS strained quantum well structures on Si substrate

The ZnSe/ZnS strained single quantum well (SSQW) and strained multiple quantum well (SMQW) structures were grown on (100)-oriented Si substrates at 150 degreesC in a horizontal cold-wall quartz reactor by low-pressure metalorganic atomic layer epitaxy (ALE) at a pressure of 30Torr. Dimethylzinc (DMZn), hydrogen sulfide (H2S) and hydrogen selenide (H2Se) were used as the reactants, X-ray diffraction (XRD), secondary ion mass spectromery (SIMS) and photoluminescence (PL) were used to characterize the strained quantum wells. The high-quality crystalline Zns(1000 Angstrom)/ZnSe(71 Angstrom )Zns(1000 Angstrom )Si-sub. SSQW structure exhibits a 32 meV full-width at half-maximum (FWHM) for the 7 K PL spectra, The PL peak emission energy dependence on the well thickness for the ZnSe/ZnS SSQW structure is in good agreement with predictions based on a parabolic well-strain mode. In addition, the well-thickness dependence of the PL peak energy and FWHM of SSQW structures are described in detail. The temperature dependence of the PL peak energy and FWHM of SMQW structures are also measured from 7 to 156 K using a He-Cd laser operated at a wavelength of 325 nm as an excitation source. Better understanding of the temperature-dependent behavior would be helpful in the optoelectronic device development. (C) 2001 Elsevier Science B.V. All rights reserved.