Epitaxial growth of high quality ZnSe on Si substrates by molecular beam epitaxy and application to dc electroluminescent cells

ZnSe thin films were grown on (100) and (111) oriented Si substrates by molecular beam epitaxy. The single-crystalline ZnSe films were obtained in the substrate temperature range of 300-450°C. The epitaxial layers were evaluated by reflection high-energy electron diffraction, x-ray diffraction, etch pit density, photoluminescence, and Hall effect measurements. Etch pit density was estimated to be 3×10⁵ cm^-2. The carrier concentration and electron mobility of the epitaxial ZnSe layers at room temperature are 1.3×10¹⁷-2.8×10 ¹⁷ cm^-3 and 170-250 cm²/V s, respectively. These epitaxial films were applied to Au/ZnSe:Mn/Si dc-operated electroluminescent cells. The maximum quantum efficiency of 2.2×10^-2 (30.4 V, 6.3×10^{- 5} A/cm²) was achieved.