In situ preparation of CdS nanoparticles imbedded in a polyelectrolyte multilayer for photocurrent generation

Abstract

CdS nanoparticles (NPs) were prepared and imbedded in polyelectrolyte multilayers (PEMs) in situ and applied to the photocurrent generation. The PEM films of the poly(propylviologen)/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) were prepared using layer-by-layer deposition. The Br- ions of the viologen groups were exchanged with S2- ion by dipping the PEMs films in a Na2S solution. Then, the films were dipped in a solution containing Cd2+ to give CdS NPs of less than 10 nm in size. The CdS NP-PEM films form an efficient acceptor-sensitizer dyad system, which showed a good photocurrent of 70 nA/cm(2) at 380 nm for a 3.5 bilayer sample.