Localized surface plasmon resonance (LSPR) of nanostructures and the interfacial charge transfer (CT) of semiconductor materials play essential roles in the study of optical and photoelectronic properties. In this paper, a composite substrate of Ag2S quantum dots (QDs) coated plasmonic Au bowtie nanoantenna (BNA) arrays with a metal–insulator–metal (MIM) configuration was built to study the synergistic effect of LSPR and interfacial CT using surface-enhanced Raman scattering (SERS) in the near-infrared (NIR) region. The Au BNA array structure with a large enhancement of the localized electric field (E-field) strongly enhanced the Raman signal of adsorbed p-aminothiophenol (PATP) probe molecules. Meanwhile, the broad enhanced spectral region was achieved owing to the coupling of LSPR. The as-prepared Au BNA array structure facilitated enhancements of the excitation as well as the emission of Raman signal simultaneously, which was established by finite-difference time-domain simulation. Moreover, Ag2S semiconductor QDs were introduced into the BNA/PATP system to further enhance Raman signals, which benefited from the interfacial CT resonance in the BNA/Ag2S-QDs/PATP system. As a result, the Raman signals of PATP in the BNA/Ag2S-QDs/PATP system were strongly enhanced under 785 nm laser excitation due to the synergistic effect of E-field enhancement and interfacial CT. Furthermore, the SERS polarization dependence effects of the BNA/Ag2S-QDs/PATP system were also investigated. The SERS spectra indicated that the polarization dependence of the substrate increased with decreasing polarization angles (θpola) of excitation from p-polarized (θpola=90°) excitation to s-polarized (θpola=0°) excitation. This study provides a strategy using the synergistic effect of interfacial CT and E-field enhancement for SERS applications and provides a guidance for the development of SERS study on semiconductor QD-based plasmonic substrates, and can be further extended to other material-nanostructure systems for various optoelectronic and sensing applications.