Continuous modulation of monolayer MoS2 optical signals using a wedge-like substrate

Raman and PL (photoluminescence) spectroscopy are effective techniques for characterizing the physical properties of transition metal dichalcogenides (TMDCs). Modulating intensities of these optical signals is crucial for the advancement of research and the subsequent application of TMDCs. However, it is challenging to continuously modulate optical signals' intensities. Herein, by using a wedge-like SiO2/Si substrate, the intensities of optical signals of monolayer MoS2 are enhanced continuously, which results in ~22 times and ~39 times gain in E 2 g 1 and A1g Raman mode, respectively, and a ~13 times gain in the PL intensity. The results are of significant importance for monolayer TMDCs' characterization and applications, e.g., optoelectronics.