Raman and Impedance Spectroscopy under Applied Dc Bias Insights on the Electrical Transport for Donor:Acceptor Nanocomposites Based on Poly(vinyl carbazole) and TiO2 Quantum Dots

摘要

In this report, we studied Raman and impedance spectroscopy under applied dc bias for poly(vinyl carbazole):titania quantum dots (PVK:TiO2-QDs) nanocomposites to understand the electrical transport in this donor:acceptor system as promising active layer materials for polymeric solar cells. The nanocomposites were synthesized using a novel strategy involving the sol-gel method via in situ water vapor flow diffusion in the polymer host leading to similar to 3-8 nm TiO2 quantum dots embedded in PVK with excellent homogeneity. Raman spectroscopy was used to monitor the presence of charge carriers in the organic semiconductor for PVK:TiO2-QDs with different TiO2 quantum dots compositions with and without applied dc voltage. The joint study of confocal Raman spectroscopy supported by theoretical simulations together with impedance spectroscopy under applied dc voltage could give us a major approach to understand the electrical transport mechanism of these hybrid donor:acceptor nanocomposites.