Chemical doping of the SnSe monolayer: a first-principle calculation

Using first-principles calculations, non-metallic doping at the Se site and metallic doping at the Sn site in a SnSe monolayer were systematically investigated. Our results showed that for non-metallic doping, the P atom acted as a highly promising p-type doping source due to its low formation energy and shallow acceptor level. However, n-type conductivity was predicted to be unfavorably realized with the substitution of F/Cl/Br atoms as they induced deep donor levels. For metallic doping, the Al atom introduced magnetism into the system and the optical absorption range was broadened due to dopant (Li, Mg, Al) modifications. These results were expected to provide a good reference for the realization of chemical doping in the SnSe monolayer.