Near-field radiative thermal rectification assisted by Bi2Se3 sheet

The ability to control heat flux at the nanoscale opens up numerous exciting possibilities in modern electronics and the field of information processing. In this research, we propose a design with the focus on achieving efficient thermal rectification at moderate gap and relatively low temperature. This study centers on near-field thermal radiation between temperature dependent indium antimonide (InSb) and silicon carbide (3C-SiC) coated with bismuth selenide (Bi₂Se₃). Our investigation sheds light on the critical role played by the Bi₂Se₃ layer in enhancing various key parameters, including the net radiative flux, and thermal rectification efficiency (η). We achieved a substantial improvement in the η of a near-field radiative thermal rectifier (NFRTR) due to the presence of the Bi₂Se₃ sheet. This enhancement is contingent on factors such as the Fermi energy (E_f) of Bi₂Se₃, emitter temperature, and the vacuum gap (d). Our study culminated in the identification of an optimal design, achieving an impressive η of 75% at an emitter temperature (T_H) of 350 K, with vacuum gap (d) set to 20 nm. Furthermore, increasing T_H to 500 K resulted in even more promising outcomes, with the highest η reaching 93%. The need for operating the optimized device at moderate temperatures is to strike a balance between efficiency, safety, cost-effectiveness, and material compatibility. These findings represent a significant step forward in the development of efficient Bi₂Se₃-based NFRTRs, paving the way for future applications in thermal management, energy conversion systems, and thermal logic gates.