Ion-driven nanograin formation in early-stage degradation of tri-cation perovskite films

Abstract

Nanoscale investigation of operational stability in perovskite films. Scanning probe microscopy is employed to reveal signs of early-stage degradation caused by the formation of local charge imbalance across the film microstructure.

Recent progress of copper halide perovskites: properties, synthesis and applications

“…For instance, as was revealed in lead halide perovskite, some A-site cations may exert no obvious effect on the emission, like methylamine or formamidine, but they apparently affect the performance and stability of perovskite devices. 103 In addition, considering the difficulty of tuning the optical properties via the B-site cation, the utilization of functional A-site cations may provide new ideas to achieve the desired optical properties. In these cases, a better understanding of A-site cations is required, which needs the combined development in both experiment and theoretical analysis.…”

Surface Passivation Suppresses Local Ion Motion in Halide Perovskites

“…To probe ion migration in these films at the local level, we combine local electric field poling with SKPM to measure the evolution of the CPD following the application of poling fields of both positive and negative bias. Figure shows the general experimental approach, which is similar to the method that Yun et al and Richheimer et al have used to study ion migration in unpassivated methylammonium (MA)-based perovskites. , …”

“…Figure 2 shows the general experimental approach, which is similar to the method that Yun et al and Richheimer et al have used to study ion migration in unpassivated methylammonium (MA)-based perovskites. 38,39 First, we perform a single pass with the cantilever to measure the topography across a single line. Next, we lift the cantilever 10 nm above the sample, apply a potential to the tip, and perform a second pass across the same line.…”

Nanoscale heterogeneity of ultrafast many-body carrier dynamics in triple cation perovskites

“…Careful inspection of AFM topography demonstrates that, while overall topographic features are well maintained even after 1 hour of constant illumination, some domains show signatures of roughening after 20 min of illumination that has been recently attributed to photoinduced nano-grain formation of PbI 2 (Supplementary Fig. S 5 E) 78 . However, PbI 2 itself is unlikely to contribute to the observed near-field pump-probe signal due to its much weaker absorption at 2.4 eV compared with the FAMACs perovskite.…”