Electric field-induced color switching of luminescence from ZnO nanoparticle/polymer

Abstract

We report on reversible switching induced by an electric field between blue-green and red cathodoluminescence (CL) in the ZnO:Mg nanoparticles/poly(4,4'-diphenylene diphenylvinylene) (PDPV) nanostructure. It has been found that the PDPV-ZnO:Mg structures shows the CL emission maximum in the blue-green region without an electric field. The positive bias voltage suppressed the blue-green emission and shifted the emission maximum to the red region. The structural and optical properties of the doped ZnO particles are investigated and the mechanism for the formation of the exited states in PDPV-ZnO:Mg nanostructures is discussed. It implies the presence of radiative recombination channels, which can be adjusted by a biased voltage to the carrier depletion or accumulation mode.