in Inert Atmospheres for Tunable Phonon and Excitonic Responses*

Laser processing of transition metal dichalcogenides (TMDCs) can selectively tune their properties, inducing phase transitions, creating patterns, or engineering defects, to precisely tailor conductivity, bandgap, and catalytic activity. Due to their remarkable electronic, optical, and mechanical characteristics, TMDCs offer great promise for innovations in electronics, photonics, and energy storage applications. In this study, we irradiated MoS₂ with a laser in an inert temperature-controlled atmosphere to gain insights into the fundamental interplay of lattice vibrations and electronic excitations in response to varying laser powers over time. We characterized the thermal evolution of Raman-active phonon modes. In parallel, photoluminescence (PL) measurements were performed across the same temperature range to monitor excitonic conversion and intensity changes. The correlation between phonon evolution and excitonic response under inert versus ambient conditions provides a tunable framework for customizing TMDCs with greater fidelity for targeted applications.