Enhanced wavelength selectivity and stability of multilayer graphene-based infrared emissivity modulator using a silicon overlayer

Ion intercalation offers a versatile method for dynamically tuning the infrared emissivity of multilayer graphene (MLG), with great potential in various applications, such as radiative cooling and thermal camouflage. However, the practical use of MLG-based emissivity modulators is limited by poor wavelength selectivity and short operational lifespans. Herein, a silicon overlayer is introduced to address these challenges. By controlling the thickness of the silicon overlayer, selective wavelength emissivity across mid-wave and long-wave infrared bands is achieved through interference effects and plasmonic resonance without compromising the capability for emissivity modulation via ion intercalation through electrostatic gating. Furthermore, the silicon overlayer significantly prolongs the device's lifespan by preventing oxidation and maintaining the structural integrity of MLG. These results present an approach to integrating optical engineering with dynamic emissivity modulation, paving the way for developing practical wavelength-selective emissivity modulators.