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.

Layered Transition Metal Dichalcogenides (TMDs) like Tungsten Disulphide (WS$_2$) possess a large direct electronic band gap ($\sim$ 2 eV) in the monolayer limit, making them ideal candidates for opto-electronic applications. The size and nature of the bandgap is strongly dependent on the number of layers. However, different TMDs require different experimental tools under specific conditions to accurately determine the number of layers. Here, we identify the number of layers of WS$_2$ exfoliated on top of SiO$_2$/Si wafer from optical images using the variation of optical contrast with thickness. Optical contrast is a universal feature that can be easily extracted from digital images. But fine variations in the optical images due to different capturing conditions often lead to inaccurate layer number determination. In this paper, we have implemented a simple Machine Learning assisted image processing workflow that uses image segmentation to eliminate this difficulty. The workflow developed for WS$_2$ is also demonstrated on MoS$_2$, Graphene and h-BN, showing its applicability across various classes of 2D materials. A graphical user interface is provided to enhance the adoption of this technique in the 2D materials research community.