An effective method to control the rate of perovskite crystallization by incorporating rationally chosen additives into the perovskite precursor solutions is demonstrated. The processing additives ...simultaneously facilitate nucleation and modulate the kinetics of crystal growth during crystallization, leading to much smoother perovskite morphology with improved coverage area and crystal uniformity. As a result, it enables very high PCE (∼12%) planar‐heterojunction solar cells to be fabricated through the low‐temperature solution processes (under 150 °C). This study opens up a new direction for optimizing perovskite active layer properties to expand device performance ceilings.
An effective approach to significantly increase the electrical conductivity of a NiOx hole‐transporting layer (HTL) to achieve high‐efficiency planar heterojunction perovskite solar cells is ...demonstrated. Perovskite solar cells based on using Cu‐doped NiOx HTL show a remarkably improved power conversion efficiency up to 15.40% due to the improved electrical conductivity and enhanced perovskite film quality. General applicability of Cu‐doped NiOx to larger bandgap perovskites is also demonstrated in this study.
Roles of fullerene‐based interlayers in enhancing the performance of organometal perovskite thin‐film solar cells are elucidated. By studying various fullerenes, a clear correlation between the ...electron mobility of fullerenes and the resulting performance of derived devices is determined. The metallic characteristics of the bilayer perovskite/fullerene field‐effect transistor indicates an effective charge redistribution occurring at the corresponding interface. A conventional perovskite thin‐film solar cell derived from the C60 electron‐transporting layer (ETL) affords a high power conversion efficiency of 15.4%.
A fully printable perovskite solar cell (PVSC) is demonstrated using a blade‐coating technique under ambient conditions with controlled humidity. The influence of humidity on perovskite's ...crystallization is systematically investigated to realize the ambient processing condition. A high power conversion efficiency of 10.44% is achieved after optimizing the blade‐coating process and, more importantly, a high‐performance flexible PVSC is demonstrated for the first time. A high efficiency of 7.14% is achieved.
Li‐rich layered oxide cathodes with conventional transition metal cation and unique oxygen anion redox reactions deliver high capacities in Li‐ion batteries. However, the oxygen redox process causes ...the oxygen release, voltage fading/hysteresis, and sluggish electrochemical kinetics, which undermine the performance of these materials. By combining operando quick‐scanning X‐ray absorption spectroscopy with online gas chromatography, the effect of the local electronic structure is elucidated on the reaction mechanism and electrochemical kinetics of Li‐rich cathodes. The local electronic structure of Li‐rich cathodes varies with the excess Li (i.e., Li2MnO3 phase) and Ni contents. Compared to the Li‐rich cathodes with higher amounts of Li2MnO3 phase (high excess lithium content (HLC) cathode), those with lower Li2MnO3 contents (low excess lithium content (LLC) cathode) exhibit reversible anion redox reactions and suppressed voltage hysteresis. The cation oxidation process of LLC cathode is kinetically slower than that of HLC cathode and the cation oxidation potential is shifted, likely due to the local coordination associated with different Li/O ratios. The obtained insights into the effect of local electronic structure on the reaction mechanism and kinetics provide a better understanding and control of Li‐rich cathodes.
This research reveals the reaction mechanism and electrochemical kinetics of Li‐rich cathodes using in operando quick‐scanning X‐ray absorption spectroscopy. With the control of Li2MnO3 domain, cation migration and voltage decay were suppressed. The electrochemical stability and kinetics of tradition metal (TM) redox can be tuned by modifying the local coordination structure of Li‐rich cathode.
Simple and solution‐processible tetrabutyl‐ammonium salts (TBAX) can dope fullerene and its derivatives to achieve conductive thin films (σ as high as 0.56 S/m). The electron transfer between the ...anions of TBAXs and n‐type semiconductors induces doping without encountering any harsh activation. These provide valid support for the surfactant interfacial doping of fullerene in polymer solar cells for enhanced device performance.
Advanced colorectal cancer (CRC) survival rates are still low despite advances in cytotoxic and targeted therapies. The development of new effective or alternative therapies is therefore urgently ...needed. Bromelain, an extract of pineapple, was shown to have anticancer effects, but its mechanisms in CRC have not been fully explored. Therefore, the roles of bromelain in CRC progression were investigated using different CRC cell lines, a zebrafish model, and a xenograft mouse model. The anticancer mechanisms were explored by assessing the role of bromelain in inducing reactive oxygen species (ROS), superoxide, autophagosomes, and lysosomes. The role of bromelain in the induction of apoptosis was also assessed. It was found that bromelain inhibited CRC cell growth in cell lines and tumor growth in the zebrafish and xenograft mouse models. It also induced high levels of ROS and superoxide, plus autophagosome and lysosome formation. High levels of apoptosis were also induced, which were associated with elevated amounts of apoptotic proteins like apoptotic induction factor, Endo G, and caspases-3, -8, and -9 according to a qPCR analysis. In a Western blot analysis, increases in levels of ATG5/12, beclin, p62, and LC3 conversion rates were found after bromelain treatment. Levels of cleaved caspase-3, caspase-8, caspase-9, and poly(ADP ribose) polymerase (PARP)-1 increased after bromelain exposure. This study explored the role of bromelain in CRC while giving insights into its mechanisms of action. This compound can offer a cheap alternative to current therapies.
We intended to explore the effect of level of frailty on, and relationship with, 1-, 3-, and 6-month postoperative emergency department visits, readmissions, and mortality. This is a prospective ...multicenter observational cohort study design. Patients aged 50 years or older treated for hip fracture (n = 245) were taken from Orthopedic wards in one medical center (n = 131) and one district hospital (n = 114) in Changhua County, Taiwan. Frailty was defined as measured by the validated Clinical Frailty Scale and categorized as robust, pre-frail, and frail. We used Kaplan-Meier analysis to estimate survival rates and Cox regression to estimate the risk of frailty associated with adverse outcomes. To examine the longitudinal associations between frailty and adverse outcome, the cross-lagged models were explored. Of the 245 patients, 55 (22.4%) were classified as frail, 113 (46.1%) as pre-frail, and 77 (31.4%) as robust. More cumulative events occurred for frail than for robust patients for each adverse outcome. Frailty has long-term effect on each adverse outcome after discharge, rather than the effect simultaneously. Targeting pre-frailty and frailty is essential for prevent adverse outcomes and improving the overall health of older adults after discharge for hip fracture.
In this research, five sizes (100 × 100, 75 × 75, 50 × 50, 25 × 25, 10 × 10 µm
) of InGaN red micro-light emitting diode (LED) dies are produced using laser-based direct writing and maskless ...technology. It is observed that with increasing injection current, the smaller the size of the micro-LED, the more obvious the blue shift of the emission wavelength. When the injection current is increased from 0.1 to 1 mA, the emission wavelength of the 10 × 10 μm
micro-LED is shifted from 617.15 to 576.87 nm. The obvious blue shift is attributed to the stress release and high current density injection. Moreover, the output power density is very similar for smaller chip micro-LEDs at the same injection current density. This behavior is different from AlGaInP micro-LEDs. The sidewall defect is more easily repaired by passivation, which is similar to the behavior of blue micro-LEDs. The results indicate that the red InGaN epilayer structure provides an opportunity to realize the full color LEDs fabricated by GaN-based LEDs.
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