Terminal group engineering of Ti3C2Tx MXene on thermal emitter performance

Ti3C2Tx MXene has emerged as a promising material for diverse nanophotonics applications. In this study, we investigate how Ti3C2Tx MXene terminal groups (–F, –O–, –OH) influence the performance of a planar thermal emitter with a VO2/SiO2/Ti3C2Tx MXene structure. By examining four variants of Ti3C2Tx MXene across the 2–20 µm spectral range, we demonstrate that the hysteresis loop threshold temperature remains constant for all MXene types due to the VO2 phase change material. The average differential emissivity (Δε) between the semiconductor and metallic states of VO2 varies significantly with terminal group composition. The VO2/SiO2/Ti3C2F2 structure exhibits the highest differential emissivity of Δε = 0.42, while VO2/SiO2/Ti3C2(OH)2 shows the lowest of Δε = 0.33. The remaining structures; VO2/SiO2/Ti3C2 and VO2/SiO2/Ti3C2O2, demonstrate intermediate differential emissivity values of Δε = 0.41 and 0.38, respectively. These findings establish a foundation for controlling emissivity in applications such as energy harvesting, thermophotovoltaics, and radiative cooling systems. The ability to tailor thermal emission through MXene terminal group engineering presents opportunities for designing tunable photonic devices with precise thermal control capabilities for the next-generation of energy management systems.