Synergistic nucleation regulation using 4,4',4''-tris(carbazol-9-yl)-triphenylamine and moisture for stably air-processed high-performance perovskite photodetectors.

Perovskite photodetectors (PPDs) offer a promising solution with low cost and high responsivity, addressing the limitations of traditional inorganic photodetectors. However, there is still room for improvement in terms of the dark current and stability of air-processed PPDs. In this study, 4,4',4''-tris(carbazol-9-yl)-triphenylamine (TCTA) was utilized as a nucleation agent to enhance the quality of perovskite films. The synergistic effect of TCTA and moisture promotes rapid nucleation of PbI2-PbCl2, resulting in an increased nucleation rate and the elimination of pinholes in the film. By employing additive engineering, we obtained a PbI2-PbCl2 layer with high coverage, leading to a low density of traps in the corresponding perovskite film. Consequently, the modified PPD exhibits a remarkable reduction in dark current density by over one order of magnitude, reaching 2.4 × 10-10 A cm-2 at -10 mV, along with a large linear dynamic range (LDR) of 183 dB. Furthermore, the resulting PPD demonstrates remarkable stability, retaining 90% of the initial external quantum efficiency (EQE) value even after continuous operation for over 3200 hours. Owing to a fast response time in the nanosecond range, the PPD could convert modulated light signals into electrical signals at a speed of 588 Kbit s-1, highlighting the great potential in the field of optical communication.

Filament coating system assists recovery of ablative fCO2 laser treatment: A split-face clinical observation.

BACKGROUND: The current nursing procedure after fractional carbon dioxide (fCO2) is complex and needs to be optimized. The present study was conducted to evaluate the assisting effect of filament coating system after fCO2 laser treatment. METHODS: Chinese individuals aged from 18 to 65 years diagnosed as photoaging or atrophic acne scar were recruited and each participant was treated with one single pass of fCO2 laser. A split face was randomly assigned as treatment side or control side. For control side, conventional procedure was topically applied respectively, including desonide cream two times for 3 days, fusidic acid cream two times for 7 days, and recombinant human epidermal growth factor (RhEGF) gel four times for 7 days; for treating side, a filament coating system was applied immediately after one application of fusidic acid cream, desonide cream and RhEGF, and removed 3 h later, for 3 days. Erythema, edema, crust, and pain on both sides were scored from 0 to 10 before and 1, 2, 4, and 7 days after fCO2 laser treatment. Stratum corneum hydration (SCH) and sebum of forehead and cheek on both sides were also measured by using Corneometer-Sebumeter. RESULTS: Twenty photoaging and 11 atrophic acne scar participants finished the observation. All of them complained of erythema, edema, crust, and pain after fCO2 laser treatment, and the scores decreased as time passed by. There were no statistical significances of erythema, edema, crust, pain, SCH, and sebum between treating side and control side at each observation time. CONCLUSION: Filament coating system was effective, safe, convenient, and economic in assisting recovery of ablative fCO2 laser, which might be a new option for additional nursing procedure.

Visible-blind ultraviolet narrowband photomultiplication-type organic photodetector with an ultrahigh external quantum efficiency of over 1 000 000.

A visible-blind ultraviolet (UV) photodetector can detect UV signals and is not interfered with by visible light or infrared light in the environment. In order to realize high-performance visible-blind UV organic photodetectors (OPDs), we design photomultiplication-type (PM-type) OPDs by using a novel strategy. Firstly, wide bandgap organic semiconductor materials, which do not absorb visible light, are selected as donors to absorb UV light. Secondly, a very small amount of C60 is used as an acceptor to trap photogenerated electrons. These accumulating electrons near the Al electrode form a potential, which leads to band bending and narrowing of the interface barrier, thereby assisting hole-tunneling injection to form a multiplication. The fabricated visible-blind UV PM-type OPDs with donor/acceptor doping ratio of 50 : 1 exhibit a narrowband response with full-width at half-maximum (FWHM) of approximately 36 nm, an ultrahigh external quantum efficiency of 1.08 × 106% and a remarkable specific detectivity of 1.28 × 1014 jones at 335 nm wavelength under -14 V bias. The UV-to-visible rejection ratio exceeds 103 by adjusting the donor/acceptor mixing ratios. The devices made with other wide bandgap organic materials also showed similar performance, indicating that this device structure provides an effective method for the preparation of high-performance visible-blind UV PM-type OPDs. In addition, we prepared a flexible visible-blind UV PM-type OPD based on a PET substrate and integrated it with a flexible OLED to fabricate a wearable UV monitor, which can visually detect the intensity of UV light.

Comparison of the Efficacy of Melasma Treatments: A Network Meta-Analysis of Randomized Controlled Trials.

Background: Melasma is an acquired pigmentation disorder with challenges in treatment because of its refractory nature and high risk of recurrence. Objectives: This study aimed to compare the efficacy and side effects of 14 common therapies for melasma using a systematic review and network meta-analysis (NMA). Methods: The PubMed, Embase, and Cochrane Library databases were searched till December 2020 using the melasma area and severity index as a therapeutic index. A total of 59 randomized controlled trials (RCTs) met the inclusion criteria and were selected. Results: The ranking of relative efficacy compared with placebo in descending order was Q-switched Nd:Yag 1,064-nm laser (QSND), intense pulsed light, ablative fractional laser (AFL), triple combined cream (TCC), topical vitamin C, oral tranexamic acid (oTA), peeling, azelaic acid, microneedles (MNs), topical tranexamic acid (tTA), tretinoin, picosecond laser, hydroquinone (HQ), and non-AFL. Moreover, QSND was more effective than HQ and tTA against melasma. The ranking of percentage (%) of side effects in ascending order for each of 14 therapies with more than 80 participants was tretinoin (10.1%), oTA (17.6%), HQ (18.2%), AFL (20.0%), QSND (21.5%), TCC (25.7%), tTA (36.75%), peeling (38.0%), and MN (52.3%). Taking both efficacy and safety into consideration, TCC was found to be the most favorable selection among the topical drugs for melasma. QSND and AFL were still the best ways to treat melasma among photoelectric devices. oTA as system administration was a promising way recommended for melasma. Among 31 studies, 87% (27/31) studies showed that the efficacy of combination therapies is superior to that of single therapy. The quality of evidence in this study was generally high because of nearly 50% of split-face RCTs. Conclusions: Based on the published studies, this NMA indicated that QSND, AFL, TCC, and oTA would be the preferred ways to treat melasma for dermatologists. However, more attention should be paid to the efficacy and safety simultaneously during the clinical application. Most of the results were in line with those of the previous studies, but a large number of RCTs should be included for validation or update. Systematic Review Registration: identifier: CRD42021239203.

Structure design and performance of photomultiplication-type organic photodetectors based on an aggregation-induced emission material.

Aggregation-induced emission (AIE) materials have shown attractive prospects in the fields of biological probes, chemical sensing, optoelectronic systems and stimuli responses. Here, we have successfully fabricated photomultiplication-type organic photodetectors based on an AIE material by designing a device structure. The high photoconductive gain was attributed to the interfacial trap-assisted hole-tunneling injection caused by MoO3 as the trap for electrons. The fabricated AIE-based photomultiplication-type organic photodetectors exhibited the figures of merits of high external quantum efficiency in excess of 60 000%, responsivity of 172 A W-1, detectivity of 3.08 × 1012 Jones, and photoresponse with a rise time of 1.69 ms. Moreover, the devices also showed good stability with a half-life of 700 hours at continuous testing under ambient conditions, which makes them one of the most stable OPDs reported so far. The results demonstrate that AIE molecules are an excellent kind of photodetective material.

An Efficient and Reusable Embedded Ru Catalyst for the Hydrogenolysis of Levulinic Acid to γ-Valerolactone.

To achieve a higher activity and reusability of a Ru-based catalyst, Ru nanoparticles were embedded in N-doped mesoporous carbon through a hard-template method. The catalyst showed excellent catalytic performance (314 h-1 turnover frequency) and recyclability (reusable five times with 3 % activity loss) for the hydrogenolysis of levulinic acid to γ-valerolactone. Compared with the mesoporous carbon without N-doping and conventional activated carbon, the introduction of N-dopant effectively improved the dispersion of Ru nanoparticles, decreased the average size of Ru nanoparticles to as small as 1.32 nm, and improved the adsorption of levulinic acid, which contributed to the increase in the activity of the catalyst. Additionally, the embedding method increased the interaction between Ru nanoparticles and carbon support in contrast with the conventional impregnation method, thus preventing the Ru nanoparticles from migration, aggregation, and leaching from the carbon surface and therefore increasing the reusability of the catalyst.