Current producing states in molecular semiconductors: photo-current from a molecular wire

TL;DR

This paper introduces a computational method combining quantum chemistry and non-equilibrium Green's functions to analyze photocurrent generation in molecular semiconductors, specifically poly-(phenylenevinylene) chains.

Contribution

It develops a novel integrated approach for modeling photocurrent in molecular wires, incorporating excitonic and charge-transfer effects with a reduced tunneling model.

Findings

Identifies key excitonic and charge-transfer states affecting photocurrent.

Develops a chain-length and field-dependent tunneling model.

Provides detailed analysis of molecular semiconducting wire responses.

Abstract

We present a methodology for computing photocurrent production in molecular semiconducting molecules. Our model combines a single-configuration interaction picture with the Schwinger-Keldysh non-equilibrium Greens function approach to compute the current response of a molecular semi-conducting wire following excitation. We give detailed analysis of the essential excitonic, charge-transfer, and dipole states for poly-(phenylenevinylene) chains of length 32 and 48 repeat units under an electric field bias and use this to develop a reduced dimensional tunneling model which accounts for chain-length and field-dependent behavior.