Femtosecond Pump-Probe Studies of Reduced Graphene Oxide Thin Films

TL;DR

This study uses ultrafast pump-probe spectroscopy to investigate hot carrier dynamics in reduced graphene oxide thin films across a wide temperature range, revealing temperature-independent energy relaxation and phase-state filling effects.

Contribution

It provides new insights into the ultrafast carrier dynamics of reduced graphene oxide, showing similarities to other graphene forms and clarifying the origin of differential transmission signals.

Findings

Hot carriers relax energy rapidly, independent of temperature.

Differential transmission remains positive at all temperatures.

Carrier dynamics are similar to other graphene types.

Abstract

The dynamics of photocarriers in reduced graphene oxide thin films is studied by using ultrafast pump-probe spectroscopy. Time dependent differential transmissions are measured with sample temperatures ranging from 9 to 300 K. At each sample temperature and probe delay, the sign of differential transmission remains positive. A fast energy relaxation of hot carriers is observed, and is found to be independent of sample temperature. Our experiments show that the carrier dynamics in reduced graphene oxide is similar to other types of graphene, and that the differential transmission is caused by phase-state filling of carriers.