Rational synthesis and tunable optical properties of quasialigned Zn_(1-x)Mg_xO nanorods

摘要

Quasialigned, single-crystal Zn_(1-x)Mg_xO (x=0-0.32) nanorods were synthesized on Si substrates by thermal evaporation. Zn_(1-x)Mg_xO nanorods grew along the [0001] crystal direction and had uniform hexagonal planes with diameters of 420-120 nm. The predominant ultraviolet luminescence could be tuned from 379 (x=0) to 305 nm (x=0.32) at room temperature. This blueshift indicated the band gap engineering in Zn_(1-x)Mg_xO nanorods. Temperature-dependent photoluminescence was used to illustrate the free-exciton emission from Zn_(1-x)Mg_xO nanorods. The exciton binding energy decreased from 59 (x=0) to 49 meV (x=0.18) and then increased to 54 meV (x=0.32).