# Hubbard NEGF Analysis of Photocurrent in Nitroazobenzene Molecular Junction

## TL;DR

This study combines experimental and theoretical approaches to analyze photocurrent behavior in nitroazobenzene molecular junctions, revealing how light frequency, temperature, and layer thickness influence current flow.

## Contribution

It introduces a Hubbard NEGF diagrammatic method to accurately simulate and understand photocurrent mechanisms in molecular junctions.

## Key findings

- Photocurrent depends on light frequency, temperature, and monolayer thickness.
- Theoretical simulations qualitatively match experimental observations.
- Mechanisms for dark and photo-induced currents are discussed.

## Abstract

We present combined experimental and theoretical study of photo-induced current in molecular junctions consisting of monolayers of nitroazobenzene oligomers chemisorbed on carbon surfaces and illuminated by UV-Vis light through a transparent electrode. Experimentally observed dependence of the photocurrent on light frequency, temperature and monolayer thickness is analyzed within first principles simulations employing the Hubbard NEGF diagrammatic technique. We reproduce qualitatively correct behavior and discuss mechanisms leading to characteristic behavior of dark and photo-induced currents in response to changes in bias, frequency of radiation, temperature and thickness of molecular layer.