MOVPE Growth and optical characterization of high-quality ZnSe-ZnS superlattices using a novel zinc adduct precursor

Abstract

ABSTRACTA novel zinc precursor adduct tetramethylmethylene diamine: dimethylzinc (TMMD:DMZn) has been used to grow ZnSe-ZnS strained layer superlattices by low pressure MOVPE at 300'C. The use of this new precursor leads to improved material purity and lower homogeneous gas phase premature reaction than in the case of dimethylzinc. Optical characterization has been made between liquid helium and room temperature. The 2K photoluminescence lines range between 2.85 eV and 3.15 eV. The 2K photoluminescence is characterized by a linewidth at half maximum ranging from 13-45 meV. Additional reflectivity and photoreflectance experiments have been carried out to measure light-hole excitons. A variational calculation of the Rydberg energies has been performed using a sophisticated trial function. The experimental data is in agreement with the theoretical value when a small conduction band offset is used.