Chronic wounds are one of the most serious complications of diabetes mellitus. Even though utilizing nitric oxide (NO) as a gas medicine to repair diabetic wounds presents a promising strategy, controlling the NO release behavior in the affected area, which is vital for NO-based therapy, still remains a significant challenge. In this work, a copper-based metal–organic framework, namely, HKUST-1, has been introduced as a NO-loading vehicle, and a NO sustained release system with the core–shell structure has been designed through the electrospinning method. The results show that the NO is quantificationally and stably loaded in the HKUST-1 particles, and the NO-loaded HKUST-1 particles are well incorporated into the core layer of the coaxial nanofiber. Therefore, NO can be controllably released with an average release rate of 1.74 nmol L–1 h–1 for more than 14 days. Moreover, the additional copper ions released from the degradable HKUST-1 play a synergistic role with NO to promote endothelial cell growth and significantly improve the angiogenesis, collagen deposition as well as anti-inflammatory property in the wound bed, which eventually accelerate the diabetic wound healing. These results suggest that such a copper-based metal–organic framework material as a controllable NO-releasing vehicle is a highly efficient therapy for diabetic wounds.

Very recently, perovskite based microdisk lasers have attracted considerable research attention. However, most of the researches are focused on the lasing spectra in bottom-up synthesized microdisks with regular shapes. The directionality, which is also essential for practical applications, has not been explored. Here we demonstrate unidirectional lasing emissions from perovskite microdisks for the first time. We synthesized the rectangle-shaped microdisks connected with straight waveguides and studied the lasing characteristics, where unidirectional emissions along the waveguides have been observed. Numerical calculations reveal that the unidirectional emissions are formed by the breaking of total internal reflections at the joints between waveguides and microdisks. Since waveguides are compatible with other photonic elements, we believe that our finding will be essential for the applications of perovskite microdisks in integrated photonic circuits and networks.

Solution‐processed lead halide perovskites have shown good applicability in both solar cells and microlasers. Very recently, the nonlinear properties of perovskites have attracted considerable research attention. Second harmonic generation and two‐photon absorption have been successfully demonstrated. However, perovskite devices based on these nonlinear properties, such as micro‐ and nanolasers have thus far not been fabricated. Here we demonstrate two‐photon pumped microlasers from CH3NH3PbBr3 perovskite microwires. These CH3NH3PbBr3 perovskite microwires are synthesized through a one‐step solution precipitation method and dispersed on a glass substrate. Under optical excitation at 800 nm, two‐photon pumped lasing action with periodic peaks is successfully observed at around 546 nm. The obtained quality (Q) factors of the two‐photon pumped microlasers are around 682, and the corresponding thresholds are about 674 µJ cm‐2. Both the Q factors and thresholds are comparable to conventional whispering‐gallery modes in two‐dimensional polygon microplates. This work is the first demonstration of two‐photon pumped microlasers in CH3NH3PbBr3 perovskite microwires. We believe our finding will significantly expand the application of perovskites in low‐cost nonlinear optical devices, such as optical limiters, optical switches, and biomedical imaging devices.

The synthesized perovskites are randomly distributed and their optical properties are fixed after synthesis. Here we demonstrate the tailoring of lasing properties of perovskite microwire via micromanipulation. One microwire has been lifted by a tungsten probe and repositioned on a nearby perovskite microplate with one end suspended in air. Consequently, the conventional Fabry-Perot lasers are completely suppressed and a single laser peak has been observed. The numerical calculations reveal that the single-mode laser is formed by the whispering-gallery mode in the transverse plane of microwire. Our research provides a simple way to tailor the properties of microwire postsynthesis.

The control of photoluminescence and absorption of lead halide perovskites plays a key role in their applications in micro- and nano-sized light emission devices and photodetectors. To date, the wavelength controls of lead halide perovskite microlasers are mostly realized by changing the halide mixture in solution. Herein, we report the postsynthetic and selective control of the optical properties of lead halide perovskites with conventional semiconductor technology. By selectively exposing a CHNHPbBr microstructure with chlorine in inductively coupled plasma, we find that the wavelengths of absorption, photoluminescence, and laser emissions of exposed structures are blue-shifted around 50 nm. Most importantly, the device characteristics such as the photoluminescence intensities and laser thresholds are well maintained during the reaction process. We believe our finding will significantly boost the practical applications of lead halide perovskite based optoelectronics.

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A hybrid structure composed of CH3NH3PbBr3 microwires and tapered fibers exhibits highly efficient light collection.

Abstract：Solution-based perovskite nanoparticles have been intensively studied in past few years due to their applications in both photovoltaic and optoelectronic devices. Here, based on the common ground between the solution-based perovskite and random lasers, we have studied the mirrorless lasing actions in self-assembled perovskite nanoparticles. After the synthesis from solution, discrete lasing peaks have been observed from the optically pumped perovskites without any well-defined cavity boundaries. The obtained quality (Q) factors and thresholds of random lasers are around 500 and 60 J/cm 2 , respectively. Both values are comparable to the conventional perovskite microdisk lasers with polygon shaped cavity boundaries. From the corresponding studies on laser spectra and fluorescence microscope images, the lasing actions are considered as random lasers that are generated by strong multiple scattering in random gain media. In additional to conventional single-photon excitation, due to the strong nonlinear effects of perovskites, twophoton pumped random lasers have also been demonstrated for the first time. We believe this research will find its potential applications in low-cost coherent light sources and biomedical detection.