Growth and photoluminescence of self-catalyzed GaP/GaNP core/shell nanowires on Si(111) by gas source molecular beam epitaxy

We report a study on self-catalyzed GaP/GaNP core/shell nanowires (NWs) grown on Si(111) by gas-source molecular beam epitaxy. Scanning electron microscopy images show that vertical and uniform GaP NWs and GaP/GaNP core/shell NWs are grown on Si(111). The density ranges from similar to 1 x 10(7) to similar to 5 x 10(8) cm(-2) across the substrate. Typical diameters are similar to 110 nm for GaP NWs and similar to 220 nm for GaP/GaNP NWs. Room temperature photoluminescence (PL) signal from the GaP/GaNP core/shell NWs confirms that N is incorporated in the shell and the average N content is similar to 0.9%. The PL low-energy tail is significantly reduced, compared to bulk GaNP. (C) 2012 American Institute of Physics. [doi:10.1063/1.3681172]