Catalyst-free direct growth of InP quantum dots on Si by MOCVD: a step toward monolithic integration

Abstract

InP quantum dots (QDs) were grown on catalyst-free Si substrates by MOCVD to study the behavior of growth of low dimensional III–V structures on Si substrates. It is found that at temperature 575 °C, uniform QDs with diameter 20–50 nm and height 6–8 nm were obtained, whereas at 600 °C, InP nanoislands with wetting layers were formed instead of QDs. From the photoluminescence measurements, blue shift of the band gap is observed with a value of 1.395 eV. The densities of the QDs were found to be 7–8 × 1013 m−2. X-ray photoelectron spectroscopy establishes the presence of InP rather than indium droplet. X-ray diffraction spectra show different surface planes of the QDs. The effect of growth temperature has been discussed.