Tungsten ‘‘dye’’ induced fast blue/violet photoluminescence from nanocrystalline silicon-silica composite thin films

Abstract

Doping of the nanocrystalline‐Si/SiO₂ composite material with tungsten results in a quenching of the ‘‘red’’ photoluminescence (PL) and an appearance of an intense blue/violet one with a spectral maximum around 2.8 eV and decay time of ≤3 ns. Unlike the green/blue PL from silanol groups, this PL is stable upon annealing and does not show any polarization memory. A possible mechanism of this PL is suggested.