Electronic processes in organic–inorganic composite P3HT with silicon nanocrystals

Abstract

The generation mechanisms and charge carrier transfer in a composite of polymer poly-3(hexylthiophene) (P3HT) and silicon nanoparticles (nc-Si) films are investigated using conductivity measurements at different temperatures and electric fields and photocurrent spectroscopy. It is shown that the widely used Gaussian disorder model for describing the electrical and optical properties of polymers is also valid for hybrid organic–inorganic materials consisting of polymer matrix with silicon nanoparticles addition. This indicates that the charge carrier transfer in such materials occurs over the localized states in the polymer part of composite material. It is shown that the nonmonotonic change in the conductivity arising upon the addition of silicon nanoparticles leads only to a change in the distribution of the density of localized states in the polymer, which determines the conductivity and photoconductivity of the hybrid material. It is demonstrated that the addition of nc-Si at lower concentrations to P3HT makes it possible to vary the conductivity and photoconductivity of the composite material over a wide range.