Unraveling the Potential of Hybrid Borocarbonitride Biphenylene 2D Network for Thermoelectric Applications: A First Principles Study

Abstract

In this study, we investigate a novel hybrid borocarbonitrides (bpn-BCN) 2D material inspired by recent advances in carbon biphenylene synthesis, using first-principles calculations and semi-classical Boltzmann transport theory. Our analysis confirms the structural stability of bpn-BCN through formation energy, elastic coefficients, phonon dispersion, and molecular dynamics simulations at 300K and 800K. The material exhibits an indirect band gap of 0.19 eV (PBE) between the X and Y points and a direct band gap of 0.58 eV (HSE) at the X point. Thermoelectric properties reveal a high Seebeck coefficient, peaking at 700 VK^(-1) for n-type carriers at 200K along the x-axis, while n-type has a maximum of 588 VK^(-1). The electrical conductivity is 2.2 ×〖10〗^7 〖Ω^(-1) m〗^(-1) for hole carriers, surpassing that of conventional 2D materials. The consequences of the high Seebeck coefficient and conductivity reflect a high-power factor with a peak value of 〖178×10〗^(-3) Wm^(-1) K^(-2) at 1000K for p-type carriers along the y-axis whereas, for n-type 〖91×10〗^(-3) Wm^(-1) K^(-2). Moreover, the highest observed ZT values were 0.78 (0.72) along the x (y) direction at 750 K for p-type and 0.57 (0.53) at 750 K along the x (y) axis for n-type. Our findings suggest that the bpn-BCN 2D network holds significant potential for thermoelectric applications due to its exceptional performance.