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Gross Raynor posted an update 2 days, 7 hours ago
Ultimately, it was demonstrated that the unintentional In incorporation in GaN barriers was induced by the evaporation of predeposited In-rich particles during low-temperature growth of GaInN wells. dBET6 research buy Such residual In contamination was sufficiently inhibited by inserting low Al fraction (∼6%) AlGaN spacers after each GaInN well. During the growth of AlGaN spacers, AlN polycrystalline particles were deposited on the surrounding dummy substrate, which suppressed the evaporation of the predeposited In-rich particles. Thus, the presence of AlGaN spacers certainly improved the uniformity of In fraction through five GaInN quantum wells and reduced the diffusion of point defects from n-core to MQS active structures. The superior coaxial GaInN/GaN MQS structures with the AlGaN spacer are supposed to improve the emission efficiency in white-/micro-LEDs.Because of the facile formation of defects in organometal halide perovskites, the defect passivation has become an important prerequisite for the stable and efficient perovskite solar cell (PSC). Regarding that ionic defects of the perovskites play a significant role on the performance and stability of PSCs, we introduce lithium fluorides as effective passivators based on their strong ionic characteristics and small ionic radii. Both Li+ and F- are observed to successfully incorporate within the perovskite layer, improving the device performances with the best efficiency over 20%, while the hysteresis effects are significantly reduced, confirming the passivation of perovskite defects. Moreover, LiF restrains both thermal degradation and photodegradation of PSCs, where over 90% of the initial efficiencies have been retained by LiF-incorporated devices for more than 1000 h under either 1 sun illumination or 85 °C thermal condition. As the trap density of states is analyzed before and after the thermal stress, not only the mitigation of electronic traps as fabricated but also the dramatic relaxation of traps during the postannealing step is observed with the LiF incorporation. From this work, LiF has shown its potential as a promising ionic passivator, and the phenomenal achievement of device stability by LiF provides a clear insight to overcome the stability issues of PSCs, a key to the commercialization of next-generation photovoltaics.Nature provides diverse inspirations for constructing mobile and functionalized micromachines. For example, artificial helical micro-/nanomotors inspired by bacteria flagella that can be precisely steered for various applications have been constructed by utilizing materials with excellent functions. Graphene-based materials show outstanding properties, and, to date, have not been considered to construct helical micromotors and investigate their potential applications. Here, we propose an interesting “microscale liquid rope-coil effect” strategy to stably and simply fabricate graphene oxide-based helical micromotors (GOFHMs) with high throughput by the capillary microfluidics technique. A range of desirable GOFHMs with different pitch, length, and linear diameter are tailored by smart parameter setting in microfluidic system (flow velocity, concentration, and so on). Afterward, graphene-based helical micromotors (GFHMs) are easily acquired by the reduction of GOFHMs and further drying. Actuated by rotating magnetic field, GFHMs show capability to conduct programmed locomotion in a microchannel. As a proof-of-concept demonstration, GFHMs and Ag modified GFHMs have been successfully applied to water remediation, which exhibits excellent removal efficiency of chemical and biological pollutants. Meanwhile, doxorubicin is modified onto GFHMs for the application of drug delivery. Accordingly, we believe that GFHMs have great potential in a variety of fields by modifying graphene with other nanoparticles or functional molecules.Here, a novel poly(dimethylsiloxane) (PDMS)-based microbial culture system was investigated. Bacteria were encapsulated in functional and semipermeable membranes, mimicking the cell microenvironment and facilitating mass transport for interrogating microbial dynamics, thereby overcoming one of the major challenges associated with commercially available PDMS such as Sylgard 184. The hydrophobic nature and lack of control in the polymer network in Sylgard 184 significantly impede the the tunability of the transport and mechanical properties of the material as well as its usage as an isolation chamber for culturing and delivering microbes. Therefore, a novel PDMS composition was developed and functionalized with dimethylallylamine (DMAA) to alter its hydrophobicity and modify the polymer network. Characterization techniques including NMR spectroscopy, contact angle measurements, and sol-gel process were utilized to evaluate the physical and chemical properties of the newly fabricated membranes. Furthermore, the DMAA-containing polymer mixture was used as a proof of concept to generate hydrodynamically stable microcapsules and cultivate Escherichia coli cells in the functionalized capsules. The membrane exhibited a selective permeability to tetracycline, which diffused into the capsules to inhibit the growth of the encapsulated microbes. The functionality achieved here with the addition of DMAA, coupled with the high-throughput encapsulation technique, could prove to be an effective testing and diagnostic tool to evaluate microbial resistance, growth dynamics, and interspecies interaction and lays the foundation for in vivo models.Alkali halide perovskites have emerged as representative candidates for novel opto-electronic devices owing to their balanced efficiency and stability. However, their fabrication method still remains a challenging topic with conflicts among their effectiveness, complexity, and cost. Herein, a complete two-step electrochemical method has been applied in the fabrication of inorganic perovskites for the first time. The dimension and microstructure of CsPbBr3 can be easily controlled by variation of simple physical parameters during the fabrication. By optimizing the parameters, high-quality CsPbBr3 films are obtained, and the champion device has achieved an efficiency of 7.86% with a high open-circuit voltage of 1.43 V. More importantly, the as-fabricated materials have shown an extraordinary robust stability against environmental conditions even after 150 days of exposure to air without encapsulation. This has evidently proved the electrochemical methods as an effective route for perovskite synthesis in its future development.