Direct growth of high-quality CdTe epilayers on Si(2 1 1) substrates by metalorganic vapor-phase epitaxy

Abstract

High-quality epitaxial CdTe layers were grown on Si(2 1 1) substrates in a metalorganic vapor-phase epitaxy. In order to obtain homo-orientation growth on Si substrates, pre-treatment of the substrates was carried out in a separate chamber by annealing them together with pieces of GaAs at 800–900 °C in a hydrogen environment. Grown epilayers had very good substrate adhesion. The full-width at half-maximum value of the X-ray double crystal rocking curve from the CdTe(4 2 2) plane decreased rapidly with increasing layer thickness, and remained between 140–200 arcsec for layers thicker than 18 μm. Photoluminescence measurement at 4.2 K showed high-intensity bound excitonic emission and very small defect-related deep emissions indicating the high crystalline quality of the grown layers.