Characterization and photoelectrochemistry of layer-by-layer self assembled films of CdS quantum dots in polyelectrolyte matrix

摘要

Photoelectrochemical studies of polyacrylate-capped CdS nanoparticles embedded in a polyelectrolyte matrix on electrode surfaces are presented. Multilayered films of polyacrylate-capped Q-CdS are assembled layer-by-layer on solid surfaces modified with a cationic polyelectrolyte, poly(diallyldimethylammonium chloride). The characterization of the layer-by- layer growth by means of UV-visible absorption, photoluminescence, FT-IR spectroscopy and ellipsometry measurements revealed the incorporation of the nanoparticles in the matrix and the reproducible surface-charge reversal taking place. In this paper, we present initial photocurrent-voltage studies of films thus formed, where the feasibility of charge conduction through the polyelectrolyte matrix and the dependence of photocurrent magnitude on the number of bilayers are demonstrated. In addition, the dependence of photocurrent direction on the electrode potential, and the observation of anodic photocurrent spikes attributed to surface states in the presence of dissolved oxygen are reported.