Growth of self-assembled InGaN quantum dots on Si (111) at reduced temperature by molecular beam epitaxy

Self-assembled InGaN quantum dots (QDs) were grown by RF plasma-assisted molecular beam epitaxy on Si (111). The growth of InGaN QDs has been investigated in situ by reflection high energy electron diffraction. It is found that a low-temperature growth of InGaN instantaneously leads to the formation of three-dimensional islands. Field emission scanning electron microscopy and atomic force microscopy revealed that diameters were small enough to expect a zero-dimensional quantum effect which is around 20 nm and the height of the dots was around 6.0 nm. X-ray diffraction (XRD) measurement indicated that the InGaN was epitaxially grown on silicon substrate. Photoluminescence measurement exhibits a sharp and intense band edge emission of InGaN at 1.7 eV. There was an excellent agreement with the result of mole fraction measured from XRD by employing Vegard's law which is In molar fraction is 0.5. - Highlights: • Low-temperature InGaN QDs was successfully grown by molecular beam epitaxy (MBE). • InGaN QD was grown on Si (111) without growth interruption by MBE. • The growths of InGaN QDs on Si (111) are less investigated compared to sapphire