First-Principles Study of Electronic Properties of Substitutionally Doped Monolayer SnP.

SnP has a great prospect in electronic and thermoelectric device applications due to its moderate band gap, high carrier mobility, absorption coefficients, and dynamical and chemical stability. Doping in two-dimensional semiconductors is likely to display various anomalous behaviors when compared to doping in bulk semiconductors due to the significant electron confinement effect. By introducing foreign atoms from group III to VI, we can successfully modify the electronic properties of two-dimensional SnP. The interaction mechanism between the dopants and atoms nearby is also different from the type of doped atom. Both SnBP and SnNP systems are indirect bandgap semiconductors, while the SnAlP, SnGaP, SnPP and SnAsP systems are metallic due to the contribution of doped atoms intersecting the Fermi level. For all substitutionally doped 2D SnP systems considered here, all metallic systems are nonmagnetic states. In addition, monolayer SnXP and SnPY may have long-range and local magnetic moments, respectively, because of the degree of hybridization between the dopant and its adjacent atoms. The results complement theoretical knowledge and reveal prospective applications of SnP-based electrical nanodevices for the future.