Guanchen Li

Graphene‐based materials combining outstanding electrical, thermal, optical and mechanical properties have demonstrated remarkable potential for high‐performance sensing across optoelectronic, molecular, mechanical, magnetic and thermal applications. However, practical graphene sensing often involves relatively small stimulus‐induced changes in diverse electrical quantities, requiring dedicated readout electronics for accurate detection and conditioning. Existing reviews rarely treat sensing mechanisms and readout architectures in a unified system co‐design context, which leaves a gap between device demonstrations and deployable systems. To bridge device transduction and circuit interfacing, a three‐level PS–EQ–RF framework is proposed, which maps physical stimuli (PS) to electrical quantities (EQ) and to readout features (RF). Guided by the framework, this review organizes graphene‐based sensors according to electrical output characteristics into four categories: voltage‐source, current‐source, resistive (RS), and capacitive (CS) sensors. Key circuit modules, representative readout topologies, and practical implementations are analyzed for each category. We further provide system‐level co‐design guidelines, including metric mapping, architecture selection, low‐noise design, and mitigation of nonidealities, and discuss the evolution, remaining bottlenecks, and future directions of graphene‐based sensing systems. This review aims to provide a systematic view of graphene‐based sensing systems and to accelerate the transition of graphene‐based sensing technologies from laboratory prototypes to practical applications.

Owing to the unique linear Dirac-cone dispersion of graphene, graphene field-effect transistors (GFETs) exhibit advantages including high carrier mobility and ambipolar transport. Leveraging these properties, GFETs provide a promising route for broadband response from terahertz (THz) to ultraviolet wavelengths and self-powered photodetection at room temperature based on photothermoelectric (PTE) effect. However, the absence of a unified modeling framework has hindered systematic device optimization and circuit-level implementation. This work presents a general modeling methodology that couples dark state transport, PTE conversion, and intrinsic noise into an integrated framework. Three sub-models are developed for the drain-to-source current and transconductance: a uniform drift model with minimum complexity, a high carrier density model for the high carrier density regime, and a low carrier density model applicable near the charge neutrality point. A virtual optical power port is introduced to represent optical excitation within circuit simulations, enabling co-design with readout electronics. Illuminated state behavior is described by the Seebeck coefficient derived from Mott's formula combined with a hot electron temperature profile. Noise is modeled using Johnson–Nyquist and 1/f components. Experimental validation on CVD-grown GFETs under 0.288 THz illumination demonstrates strong agreement between predictions and measurements. This work establishes a systematic modeling framework for GFET PTE detectors by integrating I–V characteristics, PTE response as well as noise behavior into a unified scheme. The framework provides a reliable foundation for device performance optimization, readout circuit design, thereby accelerating the transition of GFET PTE detectors from laboratory prototypes to practical optoelectronic systems.