Phonon-limited mobility for novel two-dimensional semiconductors of BC3 and C3N: First-principles calculation

BC3 and C3N are all novel two-dimensional (2D) semiconductors with excellent thermodynamic stability and high lattice thermal conductivity. To obtain accurate results, phonon-limited carrier mobility is investigated by an iterative Boltzmann transport equation (IBTE) including electron-phonon interaction (EPI) matrix elements for each scattering process. The piezoelectricity (PE) and polar optical phonon (POP) are not the main scattering sources. The mobility is mainly dominated by the short-range interaction between electrons and phonons. At 300 K, the electron mobility for BC3 and C3N is predicted to be 6.56 x 10(2) and 8.54 x 10(2) cm(2)V(-1)s(-1), while the hole mobility is estimated to be 9.60 x 10(1) and 3.26 x 10(3) cm(2)V(-1)s(-1). High mobility suggests that C3N is a promising material in nanoelectronic device. Furthermore, the deformation potential theory (DPT) based on longitudinal acoustic phonon (LAP) and optical phonon (OP) scattering is used to investigate mobility. The contribution of three valleys, light and heavy electrons or holes to mobility is considered in the calculation, which can effectively avoid overestimation of mobility. The carrier mobility calculated from DPT is lower than that from IBTE. Too many assumptions make the semiempirical models unable to correctly describe the complex EPI.