Photo-induced charge transfer across the interface between organic molecular crystals and polymers

TL;DR

This study investigates photo-induced charge transfer at the interface between organic semiconductors and polymers, demonstrating how light and electric fields influence charge movement and transfer rates.

Contribution

It provides direct measurement of charge transfer rates across organic interfaces under illumination, highlighting the role of electric fields and light intensity in controlling transfer direction and magnitude.

Findings

Charge transfer occurs when photon energy exceeds the semiconductor's absorption edge.

Transferred charges are immobilized in the polymer, shifting the field-effect threshold.

Transfer rate depends on electric field strength and light intensity.

Abstract

Photo-induced charge transfer of positive and negative charges across the interface between an ordered organic semiconductor and a polymeric insulator is observed in the field-effect experiments. Immobilization of the transferred charge in the polymer results in a shift of the field-effect threshold of polaronic conduction along the interface in the semiconductor, which allows for direct measurements of the charge transfer rate. The transfer occurs when the photon energy exceeds the absorption edge of the semiconductor. The direction of the transverse electric field at the interface determines the sign of the transferred charge; the transfer rate is controlled by the field magnitude and light intensity.