Fabrication and optical properties of vertically aligned ZnSe nanowire arrays catalyzed by Ga and Ag

Vertically aligned ZnSe nanowire arrays have been grown on GaAs(111) B substrates by metal-organic chemical vapor deposition using Ga and Ag catalysts. Regardless of the catalysts, the nanowires are of zinc blende structure and grow along the < 111 > B direction. However, the catalysts were found to affect the optical properties of the arrays. The dominant peak in the near-band-edge emission spectrum (10 K) of Ga-catalyzed nanowires is attributed to excitons bound to Ga donors and the corresponding peak in the spectrum of Ag-catalyzed nanowires to Ag acceptor complexes. Thus, Ga and Ag can serve both as an effective catalyst and a dopant for the growth of ZnSe nanowires.