Synthesis and characterization of monolayer Er-doped MoS2 films by chemical vapor deposition

Herein, we firstly present Er-doped MoS₂ films with a quasi-closed crucible method in chemical vapor deposition (CVD) system. ErCl₃·6H₂O is exploited as the dopant and assistant agent. The Raman analysis indicates that doped samples are uniform and high crystalline quality which has two prominent peaks with the minimum FWHM ~4 cm⁻¹ of E_2g¹. However, Er dopant caused a red-shift in PL spectra. Furthermore, doped samples present a clear absorption edge at 1.8 eV and a small split peak of B exciton, which is attributed to the formation of impurity levels in Er-doped MoS₂ based on the DFT calculations.