Investigating the thermal transport in gold decorated graphene by opto-thermal Raman technique

Abstract

We report a systematic study on the thermal transport properties of gold nanoparticles (Au NPs) decorated single-layer graphene (SLG) on a SiO2/Si substrate by the Opto-thermal Raman technique. Our results, with moderate Au NPs coverage( <10%), demonstrate an enhancement in the thermal conductivity of graphene by ~ 55% from its pristine value and a decrement in the interface conductance by a factor of 1.5. A detailed analysis of our results shows the importance of the photo-thermal conversion efficiency of Au NPs, plasmon-phonon coupling and lattice modifications in the graphene developed after gold nanoparticles deposition in enhancing the thermal conductivity and reducing the interface thermal conductance of the system. Our study paves way for a better understanding of the thermal management in such hybrid systems, which are envisioned as excellent candidates for optoelectronics and photonics applications.

Plasmonic hot carrier injection from single gold nanoparticles into topological insulator Bi2Se3 nanoribbons

“…2,6 TIs with their spin-textured surface states find applications in quantum computing, spintronics, photonics, fibre lasers, and optoelectronic devices. [7][8][9][10] Bismuth selenide (Bi 2 Se 3 ) is considered an ideal candidate for realizing intriguing phenomena associated with TIs due to its surface state band structure of Dirac-like linear dispersion with a bulk energy band gap of about 0.3 eV, which is significantly larger than the room temperature energy scale of around 25 meV. 6,11 Moreover, the Dirac point of Bi 2 Se 3 is supposed to be within the bulk bandgap and not buried in the bulk bands as in bismuth telluride (Bi 2 Te 3 ) and antimony telluride (Sb 2 Te 3 ).…”

“…Device applications requiring Dirac materials demand detailed understanding of the role of contacts and carrier injection in controlling their relativistic surface states. 8,12 The interface between the conducting surface states of Bi 2 Se 3 and metals has been theoretically studied. 13,14 Most of these theories are concerned with the generation of hot plasmonic carriers and their injection into the semiconductors interface and molecular surfaces.…”

“…12,18 In graphene-based devices, hot electron-hole pairs increase local electron densities and generate photocurrents. 19,20 The local manipulation of relativistic quantum states of nanostructures with AuNPs is an emerging research field 8,21,22 and in this fashion, the surface states of Bi 2 Se 3 can be engineered into future device requirements by locally manipulating the electronic band structure in nanostructures. 23 The hot photoinjected electrons interact with the relativistic quantum states of TIs and couple to the surface phonon modes.…”