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.
Solution-processed nickel oxides (s-NiO x ) are used as hole injection and transport layers in solution-processed organic light-emitting diodes (OLEDs). By increasing the annealing temperature, the ...nickel acetate precursor fully decomposes and the s-NiO x film shows larger crystalline grain sizes, which lead to better hole injection and transport properties. UV–ozone treatment on the s-NiO x surface is carried out to further modify its surface chemistry, improving the hole injection efficiency. The introduction of more dipolar species of nickel oxy-hydroxide (NiO(OH)) is evidenced after the treatment. Dark injection–space charge limited (DI–SCL) transient measurement was carried out to compare the hole injection efficiency of s-NiO x and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole injection layers (HIL). The UV–ozone treated s-NiO x shows significantly better hole injection, with a high injection efficiency of 0.8. With a p-type thin film transistor (TFT) configuration, the high-temperature annealed s-NiO x film shows a hole mobility of 0.141 cm2 V–1 s–1, which is significantly higher compared to conventional organic hole transport layers (HTLs). Because of their improved hole injection and transport properties, the solution-processed phosphorescent green OLEDs with NiO x HIL/HTL show a maximum power efficiency of 75.5 ± 1.8 lm W–1, which is 74.6 + 2.1% higher than the device with PEDOT:PSS HIL. The device with NiO x HIL/HTL also shows a better shelf stability than the device with PEDOT:PSS HIL. The NiO x HIL/HTL is further compared with PEDOT:PSS HIL/N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) HTL in the thermal-evaporated OLEDs. The device with NiO x HIL/HTL shows a comparable efficiency at high electroluminescence (EL) intensities.
An experiment was conducted to investigate the supplementation of direct-fed microbials (DFM) as an alternative to antibiotics on growth performance, immune response, cecal microbial population, and ...ileal morphology of broiler chickens. A total of 800 one-day-old male broiler chicks (Ross × Ross) were randomly allotted to 4 dietary treatments with 4 replicate pens per treatment (50 birds/replicate pen). The 4 dietary treatments fed for 35 d were a corn-soybean meal basal diet (control); control plus 0.1% virginiamycin, as an antibiotic growth promoter (AGP); control plus 0.1% direct-fed microbials that contained Lactobacillus reuteri (DFM 1); and control plus 0.1% direct-fed microbials that contained a mixture of L. reuteri, Bacillus subtilis, and Saccharomyces cerevisiae (DFM 2). Results showed that dietary AGP and DFM supplementation significantly increased (P < 0.05) the BW gain of broilers during 0 to 21 d. The feed intake was reduced, whereas the feed conversion was improved significantly when birds were fed DFM 2 at 0 to 7 d of age. The white blood cell and monocyte levels were significantly higher in the DFM 2 group compared with the control. In addition, feeding DFM significantly (P < 0.05) increased the plasma immunoglobulin levels where a higher level was observed in DFM 2 compared with those of the other treatments. Neither DFM nor AGP treatments affected the cecal Lactobacillus and Salmonella content; however, cecal Escherichia coli content significantly decreased in broiler chickens fed DFM and AGP. The ileal villus height, and width and total thickness of muscularis externa were significantly increased when birds were fed DFM compared with AGP and control. These results indicate that the dietary supplementation of DFM increases the growth performance of birds at an early age, stimulates the immune response, decreases the number of E. coli, and improves the ileal morphology of broiler chickens. Thus, DFM that contained a mixture of several beneficial microorganisms could be a viable alternative to antibiotics in the broiler diets.
A simple and effective method to prepare air‐processable perovskite films is developed. The blade‐coated perovskite films feature self‐assembled air‐protection patches, and solar cells based on ...these film showed significantly improved air‐stability with high power conversion efficiencies up to 9.52%. It is also demonstrated that the blade‐coating process is applicable to the fabrication of high efficiency (12.21%) perovskite solar cells.
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.
Electron donor (D)–acceptor (A)-type conjugated polymers (CPs) have emerged as promising semiconductor candidates for organic field-effect transistors. Despite their high charge carrier mobilities, ...optimization of electrical properties of D–A-type CPs generally suffers from complicated post-deposition treatments such as high-temperature thermal annealing or solvent-vapor annealing. In this work, we report a high-mobility diketopyrrolopyrrole-based D–A-type CP nanowires, self-assembled by a simple but very effective solvent engineering method that requires no additional processes after film deposition. In situ grown uniform nanowires at room temperature were shown to possess distinct edge-on chain orientation that is beneficial for lateral charge transport between source and drain electrodes in FETs. FETs based on the polymer nanowire networks exhibit impressive hole mobility of up to 4.0 cm2 V–1 s–1. Moreover, nanowire FETs showed excellent operational stability in high temperature up to 200 °C because of the strong interchain interaction and alignment.
Plant-derived anthraquinones were evaluated in cell assays for their inhibitory activities against the parasitic protozoa
human strain G3 that causes the sexually transmitted disease trichomoniasis ...in women,
bovine strain D1 that causes sexually transmitted diseases in farm animals (bulls, cows, and pigs),
-like strain C1 that causes diarrhea in domestic animals (cats and dogs), and bacteria and fungi. The anthraquinones assessed for their inhibitory activity were anthraquinone, aloe-emodin (1,8-dihydroxy-3-hydroxymethylanthraquinone), anthrarufin (1,5-dihydroxyanthraquinone), chrysazin (1,8-dihydroxyanthraquinone), emodin (1,3,8-trihydroxy-6-methylanthraquinone), purpurin (1,2,4-trihydroxyanthraquinone), and rhein (1,8-dihydroxy-3-carboxyanthraquinone). Their activities were determined in terms of IC
values, defined as the concentration that inhibits 50% of the cells under the test conditions and calculated from linear dose response plots for the parasitic protozoa, and zone of inhibition for bacteria and fungi, respectively. The results show that the different substituents on the anthraquinone ring seem to influence the relative potency. Analysis of the structure-activity relationships in protozoa indicates that the aloe-emodin and chrysazin with the highest biological activities merit further study for their potential to help treat the diseases in women and domestic and farm animals. Emodin also exhibited antifungal activity against
. The suggested mechanism of action and the additional reported beneficial biological properties of anthraquinones suggest that they have the potential to ameliorate a broad spectrum of human diseases.
We have rationally designed a densely packed 1:1 donor–acceptor (D–A) cocrystal system comprising two isometric distyrylbenzene- and dicyanodistyrylbenzene-based molecules, forming regular ...one-dimensional mixed stacks. The crystal exhibits strongly red-shifted, bright photoluminescence originating from an intermolecular charge-transfer state. The peculiar electronic situation gives rise to high and ambipolar p-/n-type field-effect mobility up to 6.7 × 10–3 and 6.7 × 10–2 cm2 V–1 s–1, respectively, as observed in single-crystalline OFETs prepared via solvent vapor annealing process. The unique combination of favorable electric and optical properties arising from an appropriate design concept of isometric D–A cocrystal has been demonstrated as a promising candidate for next generation (opto-)electronic materials.
A new 2:1 donor (D):acceptor (A) mixed‐stacked charge‐transfer (CT) cocrystal comprising isometrically structured dicyanodistyrylbenzene‐based D and A molecules is designed and synthesized. Uniform ...2D‐type morphology is manifested by the exquisite interplay of intermolecular interactions. In addition to its appealing structural features, unique optoelectronic properties are unveiled. Exceptionally high photoluminescence quantum yield (ΦF ≈ 60%) is realized by non‐negligible oscillator strength of the S1 transition, and rigidified 2D‐type structure. Moreover, this luminescent 2D‐type CT crystal exhibits balanced ambipolar transport (µh and µe of ≈10−4 cm2 V−1 s−1). As a consequence of such unique optoelectronic characteristics, the first CT electroluminescence is demonstrated in a single active‐layered organic light‐emitting transistor (OLET) device. The external quantum efficiency of this OLET is as high as 1.5% to suggest a promising potential of luminescent mixed‐stacked CT cocrystals in OLET applications.
A novel 2D‐type slab crystal based on 2:1 donor:acceptor mixed‐stacked charge‐transfer (CT) complex is developed. Unique optoelectronic properties: balanced ambipolar transport (µe, µh ≈ 10−4 cm2 V−1 s−1) and bright luminescence (ΦF ≈ 60%) are successfully bridged in organic field‐effect transistor (OFET) devices, demonstrating the first CT organic light‐emitting transistors with high external quantum efficiency up to 1.5%.
We report on a molecularly tailored 1:1 donor–acceptor (D‐A) charge‐transfer (CT) cocrystal that manifests strongly red‐shifted CT luminescence characteristics, as well as noteworthy reconfigurable ...self‐assembling behaviors. A loosely packed molecular organization is obtained as a consequence of the noncentrosymmetric chemical structure of molecule A1, which gives rise to considerable free volume and weak intermolecular interactions. The stacking features of the CT complex result in an external stimuli‐responsive molecular stacking reorganization between the mixed and demixed phases of the D‐A pair. Accordingly, high‐contrast fluorescence switching (red↔blue) is realized on the basis of the strong alternation of the electronic properties between the mixed and demixed phases. A combination of structural, spectroscopic, and computational studies reveal the underlying mechanism of this stimuli‐responsive behavior.
To mix or not to mix: A donor–acceptor (D‐A) charge‐transfer (CT) crystalline film was designed to realize stimuli‐responsive reversible fluorescence switching media. Owing to the loosely packed CT state, reorganization between the red‐emissive mixed CT phase and blue‐emissive demixed self‐sorted phase can be demonstrated by external triggers such as solvent, thermal, and piezomechanical stimuli.
PDF
