biostudies-literatureCirera BDeutsche ForschungsgemeinschaftJapan Science and Technology Agency2170-2176https://www.ebi.ac.uk/biostudies/studies/S-EPMC8949761biostudies-literatureUnknown22(6)Charge-transfer enhancement of Raman scattering plays a crucial role in current-carrying molecular junctions. However, the microscopic mechanism of light scattering in such nonequilibrium systems is still imperfectly understood. Here, using low-temperature tip-enhanced Raman spectroscopy (TERS), we investigate how Raman scattering evolves as a function of the gap distance in the single C₆₀-molecule junction consisting of an Ag tip and various metal surfaces. Precise gap-distance control allows the examination of two distinct transport regimes, namely tunneling regime and molecular point contact (MPC). Simultaneous measurement of TERS and the electric current in scanning tunneling microscopy shows that the MPC formation results in dramatic Raman enhancement that enables one to obNano lettersCharge Transfer-Mediated Dramatic Enhancement of Raman Scattering upon Molecular Point Contact Formation.PMC8949761JPMJFR201J182087777 - SFB 951Cirera BLin CAkkoush AKumagai TRossi MLitman YWolf MHammud AfalseCharge Transfer-Mediated Dramatic Enhancement of Raman Scattering upon Molecular Point Contact Formation.Charge-transfer enhancement of Raman scattering plays a crucial role in current-carrying molecular junctions. However, the microscopic mechanism of light scattering in such nonequilibrium systems is still imperfectly understood. Here, using low-temperature tip-enhanced Raman spectroscopy (TERS), we investigate how Raman scattering evolves as a function of the gap distance in the single C₆₀-molecule junction consisting of an Ag tip and various metal surfaces. Precise gap-distance control allows the examination of two distinct transport regimes, namely tunneling regime and molecular point contact (MPC). Simultaneous measurement of TERS and the electric current in scanning tunneling microscopy shows that the MPC formation results in dramatic Raman enhancement that enables one to ob2022-01-01T00:00:00Z2022 Mar2025-04-04T07:33:40.581Z2025-04-04T07:33:40.581ZS-EPMC89497613518840010.1021/acs.nanolett.1c02626