Efficient charge transfer and nonlinear optical performance of Ag&WS2 composites via deposition promoting, interface anchoring and internal doping engineering

Addressing the co-modulation of strain and interfacial effects on the nonlinear optical (NLO) behavior and conversion efficiency in noble metal and two-dimensional transition metal chalcogenide (TMD) composites, this study tackles key scientific challenges related to NLO conversion efficiency and charge transfer regulation. Herein, Ag&WS₂ composites are synthesized through controlled growth, doping, and surface anchoring/promotion strategies, enabling the modulation of ultrafast time-domain optical absorption mechanisms in WS₂. This modulation is achieved via surface plasmon resonance absorption, separated excited states, and charge transfer channels constructed by metallic components. Furthermore, density functional theory calculations and transient absorption experiments reveal interface contact charge doping, stress-induced light-medium coupling effects, and ultrafast charge transfer mechanisms. By adjusting the Ag content and contact mode, and by analyzing strain modulation at the surface/interface, precise control over ultrafast laser-induced nonlinear absorption behavior was achieved. These findings highlight the crucial role of charge transfer between excited states and exciton-phonon coupling in NLO modulation and photoelectric conversion in composite materials, along with the control mechanisms of surface-localized strain generation and charge distribution. This research provides a theoretical foundation and experimental support for the design of novel NLO materials, offering significant implications for their practical application in optoelectronic devices.