Metal halide perovskite‐based high‐performance X‐ray scintillator is considered as one of the most favorable candidates applied in the fields of medicine, industry, and science. However, the current X‐ray scilltillators based on perovskites still suffer from the issue of poor stability, which impedes their further wide applications. Herein, a template assembled method to prepare large‐size, flexible, and stable CsPbBr3@Polymethyl methacrylate composite films in ambient conditions is developed and their detection performance is studied. The composite films can maintain 94% and 81% of the initial PL intensity after 2000 cycles bending and storing in water over 2520 h, respectively. In addition, the prepared scintillators exhibit not only a low detection limit of 40.1 nGyair s−1 and a high spatial resolution of 8.0 lp mm−1, but also an excellent tolerance against radiation (108 h). Thus, this simple but yet effective method would not doubt pave the way for further development of scintillators and might be well applicable to other metal halides.

Owing to the excellent optical properties, white light‐emitting diodes (WLEDs) based on metal halide perovskites have attracted great attention as promising light source for solid‐state lighting and wireless visible light communication (VLC). However, the instability and toxicity of classic hybrid lead halides hinder their practical applications. Here, a pressure‐assisted cooling method is developed to grow lead‐free Cs3Cu2I5 and CsCu2I3 single crystals, which exhibit more excellent stability, larger size and uniform orientations in comparison with pressure‐free cooling method. Then, both single crystals are used as the emitters of WLEDs without encapsulation, exhibiting a high Color Rendering Index of 91, a decent Commission Internationale de l'Eclairage coordinate of (0.33, 0.33), a proper Correlated Color Temperature of 5436 K, as well as an excellent 1350‐h operating stability at atmosphere. Furthermore, the prepared WLEDs are utilized in wireless VLC, which possesses a −3 dB bandwidth of 10.1 MHz.

No abstract

No abstract

The severe recombination of carriers and poor stability against moisture environment have limited the application of CsPbX3 (X = Cl, Br, I) nanocrystals in photodetection. Herein, a large‐scale synthesis of SnO2‐coated CsPbBr3 NCs (abbreviated to CsPbBr3@SnO2 NCs) has been reported for the first time by combining the water‐triggered transformation of Cs4PbBr6 NCs and the hydrolysis of tin 2‐ethylhexanoate. Owing to the construction of the CsPbBr3/SnO2 heterojunction, the recombination rate of carriers in the CsPbBr3@SnO2 NCs is greatly reduced compared to that of the pristine CsPbBr3 NCs. The stability against water degradation is also improved due to the protection of the SnO2 coating. Accordingly, a CsPbBr3@SnO2‐graphene hybrid device for high‐performance photodetection is demonstrated. Results show that the responsivity of the device reaches 6.2 ×$\ \ensuremath{\times{}}$104 A W−1 at 1 V, which is over 496‐fold of the pristine CsPbBr3 device. This work not only provides a robust approach for the surface modification of CsPbX3 NCs but also offers useful guidance on the optoelectronic applications with CsPbX3 NCs.