Mn-Intercalation-Induced Burstein–Moss Shift and Broadband Emission in MoSe₂

Mn intercalation in molybdenum diselenide (MoSe₂) is explored as a strategy to tune the optoelectronic properties of transition metal dichalcogenides (TMDs). We demonstrate that Mn preferentially occupies an interstitial site in a divalent state, donating two electrons to the conduction band of MoSe₂ and inducing a Burstein-Moss blue shift of the band gap. Mn-intercalated samples further exhibit broadband emission arising from combined MoSe₂ excitonic transitions and Mn-related states, supported by first-principles calculations. Activation energies of excitonic emissions, estimated independently from Burstein-Moss shifts and temperature-dependent photoluminescence (PL), show good agreement. Temperature coefficients of all PL peaks were also extracted, offering insights into the recombination pathways in the intercalated system. These findings advance the understanding of intercalation effects in TMDs and highlight the potential of Mn-intercalated TMDs for tunable optoelectronic applications.