title: Dipole-induced conductivity enhancement by n-type inclusion in a p-type system: α-Fe₂O₃-PEDOT:PSS nanocomposites.
abstract: Hematite (α-Fe2O3) nanoparticles of two different shapes but of same size (ca. 40 nm) were dispersed in PEDOT:PSS matrices in various concentration ranges (0-7 wt%) to study the consequent changes in conductivity in the dark and under solar illumination conditions. Within a distinct range of concentration, a distinct increase in the conductivity was observed for both spherical and cubical particle population. We ascribed this effect to the generalized Poole-Frenkel theory of conduction in conjunction with the basic depletion width properties of heterojunctions and electrostatic dipole moments, and verified our assumptions through data fitting. A difference in conductivity between sphere- and cube-based α-Fe2O3-PEDOT:PSS nanocomposites was also observed and ascribed to the electrostatic edge effect on the nanoparticles. The dispersion of α-Fe2O3 nanocrystals was confirmed by high-resolution electron microscopy, whereas the electrical properties and modulations thereof were followed by recording current-voltage characteristics.
authors: Institute for Inorganic Chemistry, University of Cologne, Greinstrasse 6, 50939 Cologne, Germany. raccis@gmail.com.
authors: R
authors: R
authors: Raccis
authors: L
authors: L
authors: Wortmann
authors: S
authors: S
authors: Ilyas
authors: J
authors: J
authors: Schläfer
authors: A
authors: A
authors: Mettenbörger
authors: S
authors: S
authors: Mathur