Effects of Strain and Plasmon Induced Doping on Raman Modes of MoS₂ Transferred on a Broadband Plasmonic Light Harvester

Recent years have witnessed an everlasting interest in light confinement using plasmonic nanoparticles (NPs) through the excitation of localized surface plasmon resonance (LSPR). However, clean metal nanoparticles (NPs) have low light harvesting efficiency and are bandwidth-limited due to their narrow, size dependent plasmonic resonances which surged the need for hybrid plasmonic devices [1]. We envisioned a multilayered plasmonic-semiconductor hybrid device with an architecture: Ag-islands/TrO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>/Ag-film. Upon irradiation, the LSPR modes of Ag islands decay non-radiatively to generate hot electrons which are accepted by TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> forming a plasmonic cavity between Ag-islands and Ag film. The cavity thickness is optimized to ensure spectral overlap with the LSPR modes of Ag islands to satisfy the strong coupling conditions. This strong coupling between the LSPR modes of Ag islands and cavity modes of TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> results in splitting of the plasmonic absorption band, boosting electric field confinement and extending the light harvesting capabilities over almost the entire visible regime of 400–700 nm as shown in Fig: 1(a). Our proposed plasmonic hybrid structure hence acts as a potential broadband light harvester.