The lack of studies on CT trions stems from the technical challenges to study charge dynamics at molecule-TMD interfaces. Photoluminescence (PL) is the predominant optical technique used to investigate monolayer TMD, where the signal can either be enhanced or quenched by molecular doping 2930 . However, PL lacks the necessary time-resolution to follow charge transfer dynamics, which occurs in femtosecond time scale, beyond the common time resolution of timeresolved PL. Transient absorption (TA) has also been applied to investigate monolayer TMD , interfacial charge transfer between two TMD layers , and between TMD and conjugated molecules However, there has been no reports on studying CT trion formation at molecule-TMD interfaces. Interfacial sensitive second harmonic generation (SHG) was also applied on pristine TMD . However, its narrow spectral coverage makes SHG difficult to differentiate electronic states, making it unsuitable to identify CT trions.