AI 中文总结
研究通过聚苯乙烯辅助湿法转移将单层MoS2与单层石墨烯集成，实现光致发光增强。利用多种技术揭示电荷转移及相关机制，确立该转移为界面工程策略，可提升MoS2石墨烯异质结构在光电器件中的潜力。
AI 中文摘要
范德华MoS2石墨烯异质结构是高性能电子和光电器件应用的有力候选者。然而，层间电荷转移通常会淬灭单层MoS2的光致发光，限制了这些异质结构在发光应用中的使用。在这项工作中，我们报告了通过聚苯乙烯辅助湿法转移过程将n型单层MoS2与单层石墨烯集成，实现了异常的光致发光增强。光致发光光谱揭示了异质结构中占主导地位的三重子到激子的转换。开尔文探针力显微镜显示，形成异质结构后MoS2的功函数增加了600 meV。这种功函数的变化以及石墨烯较高的功函数表明电子从MoS2转移到石墨烯。石墨烯G和2D拉曼模式的变化进一步证实了层间电荷转移。X射线光电子能谱证明了异质结构形成后石墨烯的羟基和环氧官能化。基于DFT的巴德电荷分析量化了这些官能团在促进层间电荷转移中的作用。总的来说，我们的发现确立了聚苯乙烯辅助湿法转移作为一种实用的界面工程策略，用于增强MoS2石墨烯异质结构中的激子发射，从而提高其在可扩展光电器件中的潜力。
英文摘要
Van der Waals MoS2 graphene heterostructures are compelling candidates for high performance electronic and optoelectronic device applications. However, the interlayer charge transfer typically quenches the photoluminescence of monolayer MoS2, limiting the use of these heterostructures in light emitting applications. In this work, we report an anomalous photoluminescence enhancement in n-type monolayer MoS2 by integrating it with monolayer graphene via polystyrene assisted wet transfer process. Photoluminescence spectroscopy reveals a dominant trion to exciton conversion in the heterostructure. Kelvin probe force microscopy shows a 600 meV increase in the work function of MoS2 upon heterostructure formation. This work function shift, together with the higher work function of graphene, signifies electron transfer from MoS2 to graphene. Shifts in the graphene G and 2D Raman modes further corroborate the interlayer charge transfer. Hydroxyl and epoxy functionalization of graphene following heterostructure formation is evidenced by X ray photoelectron spectroscopy. DFT based Bader charge analysis quantifies the role of these functional groups in facilitating interlayer charge transfer. Collectively, our findings establish polystyrene assisted wet transfer as a practical interface engineering strategy for enhancing excitonic emission in MoS2 graphene heterostructures, thereby advancing their potential for scalable optoelectronic devices.
