Designing hybrid graphene oxide- gold nanoparticles for nonlinear optical response: Experiment and theory

TL;DR

This paper presents a novel hybrid graphene oxide-gold nanoparticle system exhibiting significantly enhanced nonlinear optical absorption through charge transfer, supported by experimental, theoretical, and first-principles studies, leading to improved optical limiters.

Contribution

It introduces a new hybrid material with enhanced nonlinear optical response via charge transfer, combining experiment, theory, and first-principles calculations.

Findings

Enhanced excited state absorption in graphene oxide with gold nanoparticles.

Charge transfer mechanism explains the nonlinear response enhancement.

Hybrid material outperforms benchmark optical limiters.

Abstract

Nonlinear optical absorption of light by materials are weak due to its perturbative nature, although a strong nonlinear response is of crucial importance to applications in optical limiting and switching. Here we demonstrate experimentally and theoretically an extremely efficient scheme of excited state absorption by charge transfer between donor and acceptor materials as the new method to enhance the nonlinear absorption by orders of magnitude. With this idea, we have demonstrated strong excited state absorption (ESA) in reduced graphene oxide that otherwise shows increased transparency at high fluence and enhancement of ESA by one orders of magnitude in graphene oxide by attaching gold nanoparticles (AuNP) in the tandem configuration that acts as an efficient charge transfer pair when excited at the plasmonic wavelength. To explain the unprecedented enhancement, we have developed a five-level rate equation model based on the charge transfer between the two materials and numerically simulated the results. To understand the correlation of interfacial charge-transfer with the concentration and type of the functional ligands attached to the graphene oxide sheet, we have investigated the AuNP-graphene oxide interface with various possible ligand configurations from first-principles calculations. By using the strong ESA of our hybrid materials, we have fabricated liquid cell-based high-performance optical limiters with important device parameters better than that of the benchmark optical limiters.