Metal Halide Perovskites Functionalized by Patterning Technologies

Metal halide perovskites (MHPs), as emerging stars, are greatly attracted due to their superior optical and optoelectrical properties. The design and construction of patterned materials have been considered as a powerful tool to improve the performance of optical and optoelectronic devices. Therefore, the marriage of MHPs and patterning technologies is expected to boost the development of perovskite-based applications with novel functions and optimized properties. Moreover, with the merits of patterning technologies, integrated and small-sized perovskite-based optoelectronic devices with compactness are foreseen. In this review, recent progress in this field is summarized, including template-assisted and template-free patterning technologies that can endow MHPs with high crystallinity, long-term stability, and special structures. Besides, the advantages and mechanisms of patterned MHPs toward high-performance applications are discussed

Precisely controllable fabrication of Er3+-doped glass ceramic fibers: novel mid-infrared fiber laser materials

We demonstrated remarkably enhanced 2.7 mu m emission in glass-ceramic (GC) fibers containing NaYF4: Er3+ nanocrystals with 980 nm excitation for the first time. The melt-in-tube technique is of scientific and technical significance for the fabrication of GC fibers in comparison to the conventional rod-in-tube technique. The obtained precursor fibers, in which the structure can be maintained well, exhibit no obvious element diffusion or crystallization during the fiber-drawing process. After a careful heat treatment, NaYF4 nanocrystals were controllably precipitated in the glass fiber core. Owing to the incorporation of Er3+ ions into the low phonon energy NaYF4 nanocrystals, enhanced 2.7 mu m emission was achieved from the Er3+-doped GC fibers, which was almost undetectable in precursor fibers due to the high phonon energy of the borosilicate glass fiber matrix. Moreover, the 2.7 mm emission lifetime was obtained due to the excellent emission properties of Er3+ in the GC fibers. The transmission loss values of precursor fibers and GC fibers at 1310 nm were measured to be 7.44 dB m(-1) and 11.81 dB m(-1), respectively. In addition, a theoretical simulation based on the rate equations and propagation equations was performed to evaluate the possibility of 2.7 mu m laser output. The excellent optical properties endow the GC fibers with potential applications for mid-infrared fiber lasers

Reversible 3D laser printing of perovskite quantum dots inside a transparent medium

Luminescent CsPbBr3 quantum dots can be written into glass using femtosecond laser pulses and thermal annealing, and erased by further femtosecond laser irradiation. The resulting quantum dot patterns could prove useful for data storage, decoration or security purposes. The three-dimensional (3D) patterning of semiconductors is potentially important for exploring new functionalities and applications in optoelectronics(1,2). Here, we show that it is possible to write on demand 3D patterns of perovskite quantum dots (QDs) inside a transparent glass material using a femtosecond laser. By utilizing the inherent ionic nature and low formation energy of perovskite, highly luminescent CsPbBr3 QDs can be reversibly fabricated in situ and decomposed through femtosecond laser irradiation and thermal annealing. This pattern of writing and erasing can be repeated for many cycles, and the luminescent QDs are well protected by the inorganic glass matrix, resulting in stable perovskite QDs with potential applications such as high-capacity optical data storage, information encryption and 3D artwork