NANO RESEARCH, cilt.15, sa.6, ss.5746-5751, 2022 (SCI-Expanded)
We computationally investigate the impact of crystal strain on the formation of native point defects likely to be formed in halide perovskites; A-site cation antisite (I-A), Pb antisite (I-Pb), A-site cation vacany (V-A), I vacancy (V-I), Pb vacancy (V-Pb), and I interstitial (1). We systematically identify compressive and tensile strain to CsPbI3, FAPbI(3), and MAPbI(3) perovskite structures. We observe that while each type of defect has a unique behaviour, overall, the defect formation in FAPbI(3) is much more sensitive to the strain. The compressive strain can enhance the formation energy of neutral I-pb and I-I up to 15% for FAPbI(3), depending on the growth conditions. We show that the strain not only controls the formation of defects but also their transition levels in the band gap: A deep level can be transformed into a shallow level by the strain. We anticipate that tailoring the lattice strain can be used as a defect passivation mechanism for future studies.