Following the SSCP protocol, the PL peak position exhibits a blueshift of over 30 meV throughout the entire monolayer flake, indicating that the macroscopic effect of this chemical treatment is p-doping (Fig. ). Importantly, the PL of monolayer WS2 is greatly enhanced, increasing by up to 200 times, as shown in Fig. and. The full width at half maximum (FWHM) of the treated PL spectra is also reduced to 26 meV, compared to 64 meV for the untreated sample. The PL spectra profile of the 2D WS2 monolayer, measured immediately post-chemical treatment at room temperature, aligns with that measured at 4K in terms of the peak position and FWHM (Fig. and Fig. ). This alignment suggests a significant suppression of defects and trions in the 2D WS2 following the SSCP. Given the PL inhomogeneity of the monolayer WS2 samples, we performed PL measurements on multiple WS2 monolayer samples. A comprehensive discussion on the statistical distribution of the PL peak position and the enhancement factor of the PL intensity with varied chemical treatments (Fig. ) is available in Supplementary Information (SI) Note 4. The PL spectra of the treated sample underwent a redshift from 2.026 eV (612 nm) over time while stored in air, stabilizing at 2.019 eV (614 nm). This uniform change across the sample likely results from strain relaxation or doping from small molecules in the air. To understand the binding chemistry between chemicals and the 2D WS2 surface, we initially modified the chemical treatment procedures and evaluated the resultant changes in the PL spectra of 2D WS2 (Fig. -S8) As shown in Fig. , following the FSH treatment, we observe a homogeneous enhancement in the PL peak intensity across the monolayer flake of 2D WS2. This is in contrast to the inhomogeneous shift in the PL peak position (For a detailed discussion, refer to Supplementary Information Note 4). The subsequent treatment with Li-TFSI results in an inhomogeneous enhancement of PL intensity across the WS2 monolayer flake. This indicates that FSH and Li-TFSI interact differently with the WS2 surface, potentially passivating distinct types of defects.