Zn doped MAPbBr3 single crystal with advanced structural and optical stability achieved by strain compensation
Mechanistic understanding of the perovskite degradation is one of the most urgent issues to push perovskite devices toward commercial applications. Surface coverings will lower the electrical injection and light extraction efficiency of perovskite. Therefore, structural modification of Zn doped perovskite has been proposed herein. Of particular interest is the direct observation of lattice structure at the atomic resolution through the cryo-TEM that the Zn doping will induce local lattice strain due to smaller ionic radius. Under light illumination, the photostriction will compensate the local lattice strain, which leads to structural stability as evidence suggests no phase transition in temperature ranges. In addition, MPZB also shows less than 3% decrease in PL intensity after 60 days. It is because the Zn doping induced a lowest defect density in MPZB SC (density of trap-state ntrp = 6.33×108 cm-3), which has been confirmed by the high performance of photodetector. Such strain compensation is expected to fundamentally improve the stability of photoelectric devices.
- This article is part of the themed collection: 2020 Nanoscale HOT Article Collection