▎ 摘　　要

Transparent conducting oxides (TCOs) and graphene have been extensively investigated as promising materials for electro-optic modulation applications due to their dynamically configurable near-infrared properties. In this study, a detailed comparison between modulators comprising either a TCO film or a graphene-insulator-graphene structure is presented, considering a conventional silicon photonic waveguide as the underlying physical system. Both in-line and resonant configurations are investigated, integrating an electro-optic switching mechanism that changes the free-carrier concentration in the configurable material by means of electrical gating. The carrier-concentration change effect is rigorously modeled using solid-state physics principles, providing a physically consistent and straightforward comparison between the investigated material platforms. The performance of the designed modulators is thoroughly evaluated in terms of the extinction ratio, insertion loss, energy consumption, and bandwidth in both TE and TM operation. On the whole, both technologies support high-performance optical modulation, with TCO designs exhibiting an up to 40% smaller footprint, with their graphene counterparts standing out for their subpicojoule-per-bit performance on a physical system as simple as the employed silicon-wire waveguide. The low insertion losses as well as the impressive over-100-GHz switching speeds suggest both TCOs and graphene as very promising material candidates for future on-chip modulation applications.