Semiconductor-based light detection finds widespread application in everyday devices. Since the fabrication of commercial photodetectors requires complex and capital-intensive equipment, a search for semiconductors with low-cost processing is essential. To this end, hybrid organic–inorganic metal halide perovskites (MHPs) have gained interest due to their facile processing, in combination with their outstanding properties, such as efficient light absorption and high carrier mobility. Recently, all-inorganic CsPbBr3 has emerged as a promising candidate for photodetection due to its favorable intermediate bandgap and superior photostability, thermal stability, and moisture stability. Different synthesis strategies have been adopted to obtain highly crystalline CsPbBr3 perovskites with a large variety in morphology and dimension, each allowing for a specific photodetector application, e.g., cameras for hand-held devices, large-area flat panel detectors, and flexible light sensors. This Review provides a comprehensive overview and evaluation of the state-of-the-art preparation and photodetector integration of CsPbBr3 single crystals, microcrystals, nanowires, thin films, and nanocrystals.

Following the rapid rise of organic metal halide perovskites towards commercial application in thin film solar cells, inorganic alternatives attracted great interest with their potential of longer device lifetime due to the stability improvement under elevated temperatures and moisture ingress. Among them, cesium lead iodide (CsPbI3) has gained significant attention due to similar electronic and optical properties to methylammonium lead iodide (MAPbI3), with a band gap of 1.7 eV, high absorption coefficient and large diffusion length, while also offering the advantage of being completely inorganic, providing a higher thermal stability and preventing material degradation. On a device level however, it seems also essential to replace organic transport layers by inorganic counterparts to further prevent degradation. In addition, devices are mostly fabricated by spin coating, limiting their reproducibility and scalability; in this case, exploring all-evaporated devices allows to improve the quality of the layers and to increase their reproducibility. In this work, we focus on the deposition of CsPbI3 by CsI and PbI2 co-evaporation. We fabricate devices with an allinorganic, all-evaporated structure, employing NiO and TiO2 as transport layers, and evaluate these devices for both photodetector and solar cell applications. As a photodetector, low leakage current, high EQE and detectivity, and fast rise and decay times were obtained; while as a solar cell, acceptable efficiencies were achieved. These all-inorganic, all-evaporated devices represent one step forward towards higher stability and reproducibility, while enabling large area-compatibility and easier integration with other circuitry and, in future, the possible commercialization of perovskite-based technology.

Crystal phase engineering of metal nano and microparticles is a new and promising route to tune their properties, complementary to their often exploited optimization via size and shape control. Ag...

All‐inorganic lead‐free Cs2AgBiBr6 double perovskites have gained significant attention due to their potential as stable and nontoxic photoactive semiconductors. Currently, it remains challenging to synthesize homogeneous microcrystals (MCs) exhibiting excellent properties, which are necessary for large‐area device integration. This work proposes a two‐step synthesis approach involving the introduction of a foreign silver cation to transform the 0D layered Cs3Bi2Br9 to 3D Cs2AgBiBr6 perovskite structure. This work has studied the cation exchange (CE) transformation mechanism by isolating intermediates to be able to follow the evolution of the crystal lattice as well as the structural and optical properties over time. Moreover, complete CE results in phase‐pure, highly crystalline Cs2AgBiBr6 MCs exhibiting excellent photonic properties, superior to their counterparts synthesized by anti‐solvent precipitation. These findings highlight the potential of CE‐induced transformation as a means of synthesizing novel, stable perovskites.