Electron-phonon coupling and hot electron thermalization in titanium nitride

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.