Controlled assembly of fluorescent multilayers from an aqueous solution of CdTe nanocrystals and nonionic carbazole-containing copolymers

Abstract

We report the controlled deposition of carbazole-containing copolymers and fluorescent CdTe nanocrystals in layer-by-layer (LbL) assembled films. In this strategy, poly(acrylic acid) (PAA) acts as an important medium to enhance the interaction between nonionic copolymers and aqueous CdTe nanocrystals. PAA has a strong coordinative interaction with CdTe nanocrystals in the acidic pH range via interaction between the carboxyl in PAA and the cadmium on the surface of CdTe. Meanwhile, the strong H-bonding interaction between PAA and pyridine groups in copolymers makes it possible to fabricate deposited film. As characterized by optical spectroscopy, IR spectroscopy and TEM, our results show that CdTe nanocrystals can be embedded into carbazole-containing copolymers using a LbL assembly technique. Moreover, the photoluminescence of the resultant films can be tuned by using copolymers with different ratios of pyridine/carbazole and CdTe solutions with different PAA concentrations. Our method provides a useful approach for the assembly of aqueous semiconductor nanocrystals and nonionic polymers with an accurately controlled layer component.