# Electron-phonon coupling and hot electron thermalization in titanium nitride

## TL;DR

This study investigates hot carrier thermalization in titanium nitride using first-principles calculations, revealing faster thermalization times than gold due to stronger electron-phonon coupling, especially in defective TiN.

## Contribution

First-principles analysis of electron-phonon interactions in TiN, including defects, providing new insights into hot carrier dynamics and thermalization times.

## Key findings

- Thermalization occurs faster in TiN than in gold.
- Defects like nitrogen vacancies increase thermalization time.
- Maximum thermalization time is about 200 femtoseconds at high electron temperatures.

## Abstract

We have studied the thermalization of hot carriers in both pristine and defective titanium nitride (TiN) using a two-temperature model. All parameters of this model, including the electron-phonon coupling parameter, were obtained from first-principles density-functional theory calculations. The virtual crystal approximation was used to describe defective systems. We find that thermalization of hot carriers occurs on much faster time scales than in gold as a consequence of the significantly stronger electron-phonon coupling in TiN. Specifically, the largest thermalization times, on the order of 200 femtoseconds, are found in TiN with nitrogen vacancies for electron temperatures around 4000 K.