Atomic force microscopy investigation of a step generation and bunching on the (100) facet of a CH3 NH3 PbI3 crystal, grown from γ-Butyrolactone

Capillary-written single-crystalline all-inorganic perovskite microribbon arrays for highly-sensitive and thermal-stable photodetectors

In recent times, as a result of its exceptional resistance to moisture and heat, cesium lead bromide (CsPbBr3) has been established as a potential high-performance perovskite material for optoelectronics, which is inclusive of photodetectors and photovoltaics. It has been demonstrated that a perovskite single crystal has major benefits over its thin-film equivalents; nevertheless, the preparation of perovskite crystal arrays for the utilisation of extensive integration is a challenging task. In this paper, we consider a simple crystallisation system, being a capillary-written system to enable the growth of single crystal microribbon arrays (MRAs) directly from a precursor solution. It is demonstrated by microstructure characterisation that CsPbBr3 MRAs are good-quality single crystals with highly-aligned crystal packing and smooth surfaces. The band-edge photoluminescence (PL) is exceptionally resilient and has a lengthy PL life of ∼62 ns. An exceptional photo-response having a particularly quick 99 μs response time and a 2496 A W-1 ultra-high responsivity is exhibited by photodetectors which are built upon these MRAs. The fact that the as-fabricated photodetectors maintain 90% of their commencing performance following 100 days of constant stress testing under ambient conditions under an illumination of 450 nm, showing exceptional operational stability, is noteworthy. A significant step towards the large-area growth of high-quality perovskite MRAs is presented by this work. This supplies favourable opportunities to build high-performance optoelectronic and nanophotonic systems.

Design Growth of MAPbI3 Single Crystal with (220) Facets Exposed and Its Superior Optoelectronic Properties

MAPbI₃ is deemed as the most prominent member in hybrid perovskites family because of its extremely optoelectronic properties. However, some issues and puzzles are still in expectation of their answers, such as stabilities, hysteresis, ferroelectricity, and so on. To bridge the distinctions between MAPbI₃ single crystal and thin films, large-size single crystals are demanded. On the contrary, crystal structure anisotropy-dependent optoelectronic properties is an inevitable topic. A series of large-size MAPbI₃ single crystals with (220) facets exposed were successfully grown, using high concentration solutions and large-size seed crystals to match growth rates of (100) and (220) facets. The optoelectronic properties of photocurrents, responsivity, EQE, and detectivity clearly showed significant anisotropy of optoelectronic properties in MAPbI₃ single crystal. According to ion migration theory, the anisotropy of optoelectronic properties was interpreted. We hope this result will be helpful to guide oriented growth MAPbI₃ thin films.