Benign Deep-Level Defects in Cesium Lead Iodine Perovskite

We perform first-principles calculations to study the formation energies, charge-state transition levels, and carrier capture coefficients of native defects in CsPbI3. It is shown that most of the energetically preferred native defects induce deep levels in the band gap; nevertheless, these deep-level defects are not efficient recombination centers. The mechanism underlying such recombination loss efficacy is revealed. We predict a carrier lifetime of a few microseconds, in agreement with the experimental measurements in vapor-deposited CsPbI3. This work offers an insight into the defect tolerance of CsPbI3.