Doping Mn2+in hybrid Ruddlesden-Popper phase of layered double perovskite (BA)4AgBiBr8

Prevention of ion migration in lead halide perovskites upon plugging the anion vacancies with PbSe islands

To circumvent the issue of halide ion exchange in perovskites, we have decorated CsPbBr3 and CsPbI3 nanocrystals with different sized PbSe nanoparticles and demonstrated that it effectively prevents anion exchange reaction in CsPbBr3/CsPbI3 nanoheterostructures (NHSs) as a consequence of halide vacancy passivation by the more covalent selenide anion.

Molecular Design of Layered Hybrid Silver Bismuth Bromine Single Crystal for Ultra-Stable X-Ray Detection With Record Sensitivity

Nowadays, weak interlayer coupling and unclear mechanism in layered hybrid silver bismuth bromine (LH-AgBiBr) are the main reasons for limiting its further enhanced X-ray detection sensitivity and stability. Herein, the design rules for LH-AgBiBr and its influence on X-ray detection performance are reported for the first time. Although shortening amine size can enhance interlayer coupling, its detection performance is severely hampered by its easier defect formation caused by enlarged micro strain. In contrast, an appropriate divalent amine design endows the material with improved interlayer coupling and released micro strain, which benefits crystal stability and mechanical hardness. Another contribution is to increase material density and dielectric constant; thus, enhancing X-ray absorption and carrier transport. Consequently, the optimized parallel device based on BDA2 AgBiBr8 achieves a record sensitivity of 2638 µC Gyair -1 cm-2 and an ultra-low detection limit of 7.4 nGyair s-1 , outperforming other reported LH-AgBiBr X-ray detectors. Moreover, the unencapsulated device displays remarkable anti-moisture, anti-thermal (>150 °C), and anti-radiation (>1000 Gyair ) endurance. Eventually, high-resolution hard X-ray imaging is demonstrated by linear detector arrays under a benign dose rate (1.63 µGyair s-1 ) and low external bias (5 V). Hence, these findings provide guidelines for future materials design and device optimization.

Perovskite-inspired materials for energy applications

Lead-halide perovskites have come to dominate the emerging photovoltaics research scene over the past decade. But whilst perovskite photovoltaics exhibit exceptional efficiencies, their limited stability, as well as the toxicity of their lead component remain challenges. This focus collection captures a snapshot of the efforts in the community to address these challenges, from modifications to the synthesis and device structure of perovskite photovoltaics to improve their stability, through to efforts to understand, develop, and improve lead-free perovskite-inspired materials (PIMs). PIMs range from direct perovskite-derivatives (e.g. CsSnI3or halide elpasolites) through to electronic analogs (e.g. BiOI). The collection discusses the application of these materials not only for solar cells, but also more broadly for photodetection, light emission, and anti-counterfeiting devices. This collection emphasizes the diversity of strategies and directions in this field, as well as its highly interdisciplinary nature.