First-Principles Study of Electronic Properties of Substitutionally Doped Monolayer SnP₃

SnP₃ 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 SnP₃. The interaction mechanism between the dopants and atoms nearby is also different from the type of doped atom. Both Sn₇BP₂₄ and Sn₇NP₂₄ systems are indirect bandgap semiconductors, while the Sn₇AlP₂₄, Sn₇GaP₂₄, Sn₇PP_24, and Sn₇AsP₂₄ systems are metallic due to the contribution of doped atoms intersecting the Fermi level. For all substitutionally doped 2D SnP₃ systems considered here, all metallic systems are nonmagnetic states. In addition, monolayer Sn₇XP₂₄ and Sn₈P₂₃Y 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 SnP₃-based electrical nanodevices for the future.