First-principles calculations on intrinsic point defects in CsPbBr₃

The formation energies and charge-transition levels of all possible intrinsic point defects in CsPbBr₃ are studied from first-principles calculations. The dominant defect under Br-rich and moderate growth condition is found to be Cs vacancy, whereas under Br-poor condition, Br vacancy becomes dominant. It is also found that the formation energy of dominant defect under Br-rich condition is quite small, thus moderate or Br-poor growth condition can help to avoid the formation of defects. Furthermore, most of the intrinsic defects only induce shallow transition levels. Defects that can create deep transition levels have quite high formation energy. Therefore CsPbBr₃ is highly defect-tolerant in terms that its good electronic quality can be maintained despite the presence of defects. The absence of bonding−antibonding interaction between the conduction bands and valence bands of CsPbBr₃ is expected to be the origin of the defect tolerance.