Lili Han,Jihao Zhao,Yifan Miao,Wenqian Zhou,Minglang Yuan,Jinghao Cui,Zhipeng Ci
Copper-based halides have emerged as promising scintillator materials for X-ray imaging, attributed to their favorable photophysical characteristics, such as negligible self-absorption, high light output, and fast decay. Within this category of materials, Cs 3 Cu 2 Cl 5 composite polymer scintillator films stand out, delivering excellent performance as flexible X-ray detector screens. However, severe scattering and light degradation induced by the inevitable agglomeration during recombination restricted the application in high-resolution and flexible X-ray imaging. In this study, a Cs 3 Cu 2 Cl 5 @PMMA film prepared by in-situ growth strategy is successfully developed, which represents uniform area, adjustable flexibility and excellent scintillation performance. The prepared large-area film exhibits green emission at 527 nm, with a high light yield, low detection limit and excellent spatial resolution. Meanwhile, the Cs 3 Cu 2 Cl 5 @PMMA film exhibits a remarkable degree of flexibility, enabling imaging applications on non-planar surfaces. Furthermore, it also demonstrates excellent resistance to high temperature environment, maintaining its high-quality imaging performance at 403 K.
Hao Chen,Rui Wang,Wenqiang Ma,Huanhuan Zhang,Lin Yang
The large-scale and continuous production of CsPbBr3@PMMA composite film is realized by the in-situ ultrasonic spray coating method at room temperature. Through embedding CsPbBr3 nanocrystals into the hydrophobic polymer framework, the as-fabricated films (20 cm × 20 cm) exhibit uniform green emissions with a relatively high PLQYs of 76%, and could maintain 80% PL intensity after 3 months storage under ambient conditions. Assembling the green-emissive CsPbBr3@PMMA film and the red-emissive KSF@PMMA film with blue LED chip, a high-performance LCD is obtained, reaching a higher saturation with 126% and 94% color gamut of NTSC and Rec.2020, respectively. This work demonstrates that ultrasonic spray coating technique could be widely used in the large-scale fabrication of uniformly high-quality perovskite films for backlight application.
Lead-free double perovskites (DP) have the potential to become a rising star in the next generation of lighting markets by addressing the toxicity and instability issues associated with traditional lead-based perovskites. However, high concentrations of hydrochloric acid (HCl) were often employed as a solvent in the preparation of most DPs, accompanied by slow crystallization at high temperatures, which not only raised the risk and cost in the preparation process, but also had a potential threat to the environment. Here, an in situ fabrication strategy was proposed to realize the crystallization of DP in the polymer at low temperature with a mild dimethyl sulfoxide (DMSO) solvent, and subsequently obtained optically well-behaved Cs2Na0.8Ag0.2BiCl6/PMMA composite films (CFs) by doping with Ag+, generating bright orange luminescence with a photoluminescence quantum yield (PLQY) of up to 21.52%. Moreover, the growth dynamics of Cs2Na0.8Ag0.2BiCl6/PMMA CFs was further investigated by in situ optical transformation, which was extended to other DP-based polymer CFs. Finally, these CFs exhibited excellent performance in optoelectronic devices and anticounterfeit printing, the results of which provide a new pathway to advance the development of lead-free DP materials in the optical field.