High-performance electronic and thermoelectric devices based on ferroelectric In₂Se₃/antimonene heterostructure

Inspired by the remarkable electronic properties of experimentally synthesized two-dimensional antimonene (Sb) and ferroelectric In₂Se₃ semiconductors, the electronic and thermoelectric properties of the ferroelectric In₂Se₃/Sb heterostructure are theoretically explored using first-principles calculations and Boltzmann transport theory. The results show that the electronic transport properties of the individual monolayers are improved in the In₂Se₃/Sb heterostructure, as evaluated with the HSE06 hybrid functional. The lattice thermal conductivity at room temperature is significantly lower for the heterostructure compared to the individual monolayers, owing to the strong coupling between optical and acoustic phonon modes, which leads to a reduction of group velocity in the In₂Se₃/Sb heterostructure. Remarkably, it exhibits low lattice thermal conductivity (up to 1.1 W K^-1 m^-1) and a high Seebeck coefficient (up to 2030 μV K^-1). The estimated figure of merit for p-type doping in the heterostructure is around 3.6 at 700 K. Furthermore, the In₂Se₃/Sb heterostructure demonstrates impressive thermoelectric conversion efficiency (up to 22%) and thermionic refrigeration efficiency (up to 23.8% of the Carnot limit) at room temperature, emphasizing its potential for advanced cooling applications. The In₂Se₃/Sb heterostructure exhibits desirable heat capacity and an improved figure of merit, highlighting its potential as a strong candidate for effective thermoelectric devices.