Spectrally Tunable 2D Material-Based Infrared Photodetectors for Intelligent Optoelectronics

The evolution of intelligent optoelectronic systems is driven by artificial intelligence (AI). However, their practical realization hinges on the ability to dynamically capture and process optical signals across a broad infrared (IR) spectrum. Central to this capability are IR photodetectors (PDs) based on 2D materials (2DMs), which offer tunable spectral responsivity and wavelength-resolved multiparameter optical information. This review examines the fundamental mechanisms and design strategies that enable spectral tunability at the frontier of 2DM-based IR PDs, elucidating how they offer unique opportunities to tailor spectral responses across a broad wavelength range through symmetry-breaking induced by geometric (geometrically tunable spectral engineering) and electric-field (electrically tunable spectral engineering) effects. These approaches collectively enable simultaneous optimization of spectral tunability and sensitivity without compromising wavelength coverage, speed, power efficiency, or scalability, while also providing polarization sensitivity, multiband detection, and self-powered operation for edge-integrated AI platforms, including computational spectroscopy, artificial vision, computing, and communications. This review outlines the key processes and integration requirements for scalable manufacturing, which are essential for establishing spectrally tunable 2DM-based IR PDs as core building blocks of intelligent optoelectronics. Ultimately, the development of spectrally tunable 2DM-based IR PDs will transform intelligent optoelectronic platforms for or with AI.