Synergistic Bridgeable Charge Transfer for Photoluminescence Modulation in Wedding-Cake-Like MoS2/CrOCl Heterostructures

Despite direct bandgap and other unique properties of monolayer (1L) MoS₂, the low photoluminescence (PL) efficiency hinders radiative recombination of excitons and limits further development in optoelectronic devices. Recently, synergizing interlayer and intralayer coupling in heterostructures has achieved significant modulation of light-matter interaction through tailored band alignment, offering potential solution to obstacles faced by MoS₂. Utilizing the high work function characteristics of CrOCl, a synergistic and bridgeable charge transfer engineering is reported to 1L MoS₂, with facilitated electron migration and abnormal PL enhancement in wedding-cake-like MoS₂/CrOCl heterostructures. Energy band calculations and surface potential characterizations reveal that the observed 26.5-fold PL enhancement is ascribed to the band offset in 1L MoS₂. Strong coupling at CrOCl interface opens an extra in-plane electron migration channel from 1L MoS₂ to multilayer-MoS₂, driving the abnormal enhancement. As an intuitive perception of in-plane charge transfer process, Au bridge is designed as conductive channel within MoS₂/CrOCl heterostructures, enabling desirable PL transition effect in 1L MoS₂ from “off state” to “on state”. Such PL transition proves that synergistic in-plane charge transfer is effectively bridgeable, transcending covalent bond limitations. These results enhance the understanding of the synergistic charge transfer mechanism in heterostructures and develop novel high-efficiency MoS₂-based optoelectronic devices.