White-light emission nanofibers obtained from assembling aqueous single-colored CdTe NCs into a PPV precursor and PVA matrix

Abstract

Nanofibers with white-light emission were directly prepared from aqueous single-colored CdTe nanocrystals (NCs), poly[p-xylene-α-(dialkyl-sulfonium halide)] [namely, the sulfonium polyelectrolyte precursor of poly(p-phenylene-vinylene) (PPV)], and poly(vinyl alcohol) (PVA) by an electrospinning technique. An interesting result was that the nanofibers gave white-light emission without further thermal transformation of the precursor into PPV and hence the photoluminescence (PL) of CdTe NCs was well maintained. The procurement of white-light emission was due to careful tuning of the interactions between CdTe NCs, PVA and the PPV precursor. Herein, PVA was an important matrix because it not only improved the blue-light emission significantly by avoiding the π–π stack quenching from the PPV precursor, but also increased compatibility between the NCs and the PPV precursor. In addition, the single-colored CdTe NCs avoided the Förster resonance energy transfer (FRET) between NCs, resulting in strong white-light emission. The use of the electrospinning technique kept the emission color of solid film almost the same as that of the liquid and as a result, nanofibers with bright white-light emission were finally obtained.