This paper investigates the properties of ZnSe nanocrystals doped with single N , P or As atoms (for p-type doping) or single F , Cl or Br atoms (for n-type doping). The crystals are simulated using the local density functional method. Structures doped with an N or Cl atom remained symmetrical, but some distortion appeared with the other dopants. We found that N is the most efficient acceptor impurity for p-type doping, while Cl is the most suitable impurity for n-type doping. In the case of heavy p-type doping, complex defects such as N Se – Zn – V Se and N Se – Zn int easily form in the structure. We found that N Se – Zn – V Se produces a deep acceptor level in the bandgap, while N Se – Zn int produces a compensating donor level in p-type doping. The latter is the main reason for that p-type ZnSe is difficult to achieve. This study is useful to researchers investigating p- and n-type doping as well as device manufacturers.
Critical assessment of the self-interaction-corrected–local-density-functional method and its algorithmic implementation