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Summary After more than a decade of organic photovoltaics making introductory steps into the market, the scientific and industrial communities keep working toward the consolidation of this technology in the market. The recent development of materials that yield simultaneously high levels of efficiency and transparency brings the opportunity to enter important niche markets, such as transparent photovoltaic windows, in which organic semiconductors might become the best alternative absorber. In this perspective, we provide an overview of the technological progress in organic photovoltaics especially relevant for target semitransparent applications, highlighting key R&D aspects that demand more attention from an industrial and product-development perspective. We conclude that strong effort is needed to develop higher-performing photoactive materials and roll-to-roll compatible interlayer materials and electrodes. Although this is already a significant research focus of the academic community, we identify that reinforcing research effort on topics such as improvement in device lifetime, color portfolio, and module design and efficiency will help in making a significant effect on changing the status of organic photovoltaics from a novel technology to a mature industry.

Objective: We describe the case of lower limb unilateral swelling due to a cystic mass (Adventitial Cystic Disease, ACD) compressing on the common femoral vein. This was misdiagnosed as a deep vein thrombosis on both CT venography and Doppler ultrasound. Method: We describe the diagnostic pathways and surgical excision of this venous adventitial cyst of the femoral vein. Conclusion: Venous adventitial cysts are a rare occurrence and diagnosis remains difficult. It often presents clinically as a DVT. Suspicions should be raised should symptoms persist despite appropriate DVT management. Surgical management include endovascular, minimally invasive procedures and complete evacuation of the mucoid cyst with excision of the cystic wall.

This study aimed to examine the hypothesis that extra molecular hydrogen (H2) produced by elemental magnesium (Mg) could alter rumen fermentation and methanogenesis in in vitro batch incubation. As elevated Mg2+ may exert negative effects on rumen fermentation, magnesium oxide (MgO) was also included for comparison. Mulberry leaf and corn grain had contrast chemical composition and thus were selected as substrates for incubation. Both elemental Mg and MgO were supplemented at two levels, i.e. 0.625 and 1.25 mmol/bottle. The in vitro incubation was performed for 48 h to measure gas production (GP), H2 gas (gH2) and methane gas (gCH4) production, dissolved H2 and CH4 concentrations, and volatile fatty acids (VFA) production. Elemental Mg or MgO supplementation increased (Plinear 0.05) in ruminal Mg2+ concentration between MgO and elemental Mg supplementation. Elemental Mg increased (P 5.5 mM) inhibits ruminal fermentation. Extra H2 produced by elemental Mg supplementation has a biological function to inhibit rumen fermentation, enhances ruminal methanogenesis and shifts the fermentation pathway from acetate to propionate production.

Coronavirus disease 2019 (COVID-19) is a major healthcare disaster in the modern times. Healthcare services must adapt to effectively juggle between pandemic management and maintenance of business-as-usual services so that both COVID-19 and non-COVID-19 patients receive appropriate clinical care. We share our experience of significant cardiac rhythm abnormalities seen in COVID-19 patients in Singapore, how the viral pandemic has affected the cardiac electrophysiology and pacing service in a large acute care general hospital and the steps taken to alleviate the negative impact.

In this work, docetaxel (DTX) was encapsulated in monomethoxy poly(ethylene glycol)-poly(e-caprolactone) (mPEG-PCL) micelles and monomethoxy poly(ethylene glycol)-poly(D, L-lactic acid) (mPEG-PLA) micelles, respectively. For the further application, the acute/genetic toxicity evaluation and pharmacokinetic/pharmacodynamic study of the two kinds of micellar nanomedicines were performed. In the study of anticancer activity in vitro and in vivo, DTX micelles showed better tumorgrowth inhibition than free DTX. The pharmacokinetic and tissue distribution studies showed that the DTX incorporated in micelles (especially in DTX-mPEG-PCL) retained significantly higher concentration in plasma and tumor tissue compared with free DTX. The acute toxicity and genotoxicity studies indicated that DTX micelles were safer than the docetaxel injection in cancer therapy and DTX-mPEG-PCL had less damage to DNA than DTX-mPEG-PLA. So the micelles had a pronounced effect on reducing acute toxicity and genotoxicity of docetaxel. In conclusion, DTX micelles were efficient and safe on breast carcinoma chemotherapy.

Background. Several studies have reported worse outcomes in women compared to men after endovascular aneurysm repair (EVAR). This study aimed to evaluate sex-specific short-term and 5-year outcomes after EVAR. Methods. A total of 409 consecutive patients underwent elective EVAR from 2004 to 2017 at two tertiary hospitals in Western Australia. Baseline, intraoperative, and postoperative variables were examined retrospectively according to sex. The primary outcome was 30-day mortality (death within 30 days after EVAR). Secondary outcomes were 30-day composite endpoint, length of stay after EVAR, 5-year survival, freedom from reintervention, residual aneurysm size after EVAR, and major adverse event rate at 5-year follow-up. Results. A cohort of 409 patients, comprising 57 women (14%) and 352 men (86%), was analysed. Female patients were older (median age, 76.8 versus 73.5 years, p=0.017). Male patients were more likely to be past smokers (40.9% versus 22.8%, p=0.005) and have a history of coronary artery bypass grafting (11.2% versus 3.5%, p=0.042) and malignancy (24.1% versus 10.5%, p=0.014). No difference in 30-day mortality or composite endpoints was demonstrated for female patients compared with male patients (3.5% versus 0.3%, p=0.052 and 31.6% versus 27.8%, p=0.562, respectively). The Kaplan–Meier curves demonstrated similar 5-year mortality outcomes amongst male and female patients (p=0.928). Long-term survival analysis adjusting for covariates demonstrated no significant difference in long-term mortality, composite endpoints, and reintervention rate between sexes. Conclusion. This study found no significant differences in 30-day and 5-year outcomes between female and male patients treated with EVAR, implying that EVAR remains a safe treatment choice for female patients.

We describe a case of incidental finding of portal vein aneurysm (PVA) identified from CT scan performed for investigation of lower back pain, measuring 26×32×28 mm in a young man. He was healthy with no history of hepato-pancreatic-biliary disease nor history of heavy alcohol intake. His liver

In this work, docetaxel (DTX) was encapsulated in monomethoxy poly(ethylene glycol)-poly(ε-caprolactone) (mPEG-PCL) micelles and monomethoxy poly(ethylene glycol)-poly(D, L-lactic acid) (mPEG-PLA) micelles, respectively. For the further application, the acute/genetic toxicity evaluation and pharmacokinetic/pharmacodynamic study of the two kinds of micellar nanomedicines were performed. In the study of anticancer activity in vitro and in vivo, DTX micelles showed better tumorgrowth inhibition than free DTX. The pharmacokinetic and tissue distribution studies showed that the DTX incorporated in micelles (especially in DTX-mPEG-PCL) retained significantly higher concentration in plasma and tumor tissue compared with free DTX. The acute toxicity and genotoxicity studies indicated that DTX micelles were safer than the docetaxel injection in cancer therapy and DTX-mPEG-PCL had less damage to DNA than DTX-mPEG-PLA. So the micelles had a pronounced effect on reducing acute toxicity and genotoxicity of docetaxel. In conclusion, DTX micelles were efficient and safe on breast carcinoma chemotherapy.

The study was to evaluate replacing corn meal (CM) by corn gluten (CG) on intake, digestibility, ruminal fermentation, CH4 emissions and microbial abundance in goats. The experiment was performed using randomized block design with 2 dietary treatments (CM and CG with 400 g/kg DM each). Replacing CM with CG increased NDF and CP intake and decreased starch intake. Goats fed CG diet had lower ruminal dissolved hydrogen (dH2) (-43%, P = 0.009) and dissolved methane (dCH4) (-30%, P = 0.001) concentrations than those fed with CM diet. An interaction between treatment and time (P = 0.03) was observed for dH2S with an increase (P

We demonstrate the co-development of organic semiconductors, passive materials and formulations with process optimization to enable the manufacture of high performance Organic Thin Film Transistor (OTFT) arrays suitable for mass production of printable display backplanes. These materials can be printed or coated to fabricate top and bottom gate OTFT's with charge carrier mobility greater than amorphous silicon.

Hyperbranched organic–inorganic hybrid conjugated polymers P1 and P2 were prepared via FeCl3-oxiditive polymerization of 4,7-bis(3-ethylhexyl-2-thienyl)-2,1,3-benzothiadiazole (A) and octa(3-ethylhexyl-2-thienyl-phenyl)polyhedral oligomeric silsesquioxane (POSS) (B) at different POSS concentrations. Compared to linear polymer PM derived from A, P1, and P2 exhibit much higher PL quantum efficiency (ϕPL-f) in condensed state with improved thermal stability. ϕPL-f of P1 and P2 increased by 80% and 400%, and the thermal degradation temperatures of P1 and P2 are increased by 35 °C and 46 °C, respectively. Light-emitting diodes were fabricated using P1, P2, and PM. While the electroluminescent spectra of both P1 and PM show λmax at 660 nm, P1 exhibits a much narrower EL spectrum and higher electroluminescence (∼500%) compared with PM at a same voltage and film thickness. The maximum current efficiency of P1 is more than seven times of that of PM. The turn-on voltages of the LEDs are in the order of P2 > PM > P1. LED prepared by blending P1 with MEH-PPV shows a maximum luminescence of 2.6 × 103 cd/m2 and a current efficiency of 1.40 cd/A, which are more than twice (1.1 × 103 cd/m2) and five times (0.27 cd/A) of LED of PM/MEH-PPV blend, respectively. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5661–5670, 2009

We demonstrate that the charge carrier extraction in double heterojunction organic photovoltaic(OPV) devices can be enhanced by inserting an UV-illuminated fluoropolymer polytetrafluoroethylene(PTFE) layer between indium–tin-oxide and the thermal evaporated copper–phthalocyanine(CuPc)/buckyball(C 60 ) organic active layers. In this work, we show that the anode work function influences the photocarrier collection characteristics, where the short-circuit current and open-circuit voltage increase from 1.6 to 4.8 mA/cm 2 and 0.41 to 0.48 V, respectively after the buffer layer insertion associated primary with the barrier decrease in the ITO/CuPc interface. This result shows the potential of UV-illuminated PTFE as a low-cost stable buffer layer for OPV devices.

Alternating conjugated copolymers comprised of 9,9-dihexylfluorene and unsubstituted/substituted thieno[3,2-b]thiophene moieties were synthesized using the Suzuki coupling reaction. The structures of these polymers were characterized, and their thermal, photophysical, electrochemical, and electroluminescent properties were investigated. By β-substitution of thieno[3,2-b]thiophene moiety with alkyl chain, the thermal, electrochemical, and electroluminescence properties of the resulted polymers were tuned. The polymers exhibited good thermal stability with decomposition temperature (Td) in the region of 308−431 °C and their glass transition temperatures (Tg) ranging from 126 to 146 °C. Incorporation of β-alkyl chain onto thieno[3,2-b]thiophene of the alternating copolymers led to lowered Tdand Tg and blue-shifted maximum wavelengths in both absorption and emission spectra. The influence of β-alkyl substitution on the conformation of the polymer chains was evaluated by simulating the optimized geometries of ...

There has been an increased interest in developing top emission organic light-emitting diodes (OLEDs) that are able to emit light from both sides of the OLED display. One important application of the top emission device structure is to achieve monolithic integration of a top-emitting OLED on a polycrystalline or amorphous silicon thin film transistors used in active matrix displays. A high performance dual-sided top-emitting polymer OLED developed in this work exhibited a total luminous efficiency of ∼5.0 cd/A at 4.0 V, which is comparable to that observed for a control device having bottom emission structure. A laser ablation technology was developed to define the pixels. The cathode separation was achieved without using the conventional reverse trapezoid type separators that are normally used for pixellated OLED displays. A prototype of semitransparent polymer light-emitting passive matrix display has a matrix of 100 × 32 with a display area of 32.25 mm by 11.15 mm.

Transparent conducting aluminum-doped zinc oxide (AZO) films have been prepared on glass substrates by radio frequency magnetron sputtering using a hydrogen-argon gas mixture at room temperature. The effect of hydrogen partial pressure on the optical and electrical properties of AZO films is investigated. The hydrogen partial pressure was varied from 0 to 1.25 x 10 -3 Pa during film growth. Polycrystalline Al-doped ZnO films having a preferred orientation with the c-axis perpendicular to the substrate were obtained with a root mean square roughness of ∼2 nm. At an optimal condition, the AZO films with a resistivity of 5.1 x 10 -4 Ωcm and an optical transparency of over 83% in the visible wavelength region are achieved. The AZO films with desired properties were used as an anode contact in polymeric electroluminescent devices and the electroluminescence performance of these OLEDs was studied.

We developed a flexible organic LED (OLED) using a top-emitting OLED (TOLED) architecture. The concept of our flexible OLED design is based on integration of a TOLED structure on an aluminum-laminated polyethylene terephthalate (Al-PET) substrate. Microcavity TOLEDs were formed for color tuning and efficiency enhancement. For a flexible TOLED with a 110-nm-thick poly (p-phenylenevinylene) light-emitting layer, it exhibited a luminous efficiency of 4.6 cd/A at 10 V. The performance of a TOLED made on a plastic substrate is analyzed and compared with that of the identical device on a rigid glass substrate. It is demonstrated that the flexible TOLED on Al-PET foil can be bent to a substantial degree without breaking.

The first soluble hyperbranched tetrahedral polymers were prepared by Suzuki coupling polycondensation reaction between tetrabromoarylmethane/silane and 9,9-dihexylfluorene-2,7-diboronic acid at low concentrations. The polymers exhibited high thermal stability with their decomposition temperatures (Tds) in the range 352−449 °C. The polymers emitted blue light highly efficiently in both solution and the solid state. The photoluminescence quantum efficiencies of the polymers in THF solution were in the range 73−99%, and those in thin films were 38−82%. The film PL spectra of the polymers exhibited similar spectral patterns to those determined in solutions, with 1−8 nm red shift in their emission maxima and 0−8 nm increase in their full width at half-maximum (fwhm) values being observed. No long wavelength excimer-like emissions at 500−600 nm, which were typical for polyfluorenes due to their self-aggregation in the solid state, were observed. Thus, the polymers were less prone to self-aggregation in the sol...

GaAs and Al/sub 0.3/Ga/sub 0.7/As epilayers grown at LT by MBE were used as insulators in the fabrication of MISFET devices. Parametric changes were used to evaluate the thermal stability of MISFET, to identify failure mechanisms and validate the reliability of these devices. The LT-Al/sub 0.3/Ga/sub 0.7/As MISFET showed superior thermal stability. The degradation in the performance of MISFET with 1000 /spl Aring/ thick LT-GaAs gate insulator was worse than those of the MESFET. On the other hand, MISFET with 250 /spl Aring/ thick LT-GaAs gate insulators exhibited stable characteristics with thermal stressing, LF (low frequency) noise studies on the TLM structures of MISFET layers exhibited 1/f noise in the LT-Al/sub 0.3/Ga/sub 0.7/As samples and 250 /spl Aring/ LT-GaAs samples; whereas the 1000 /spl Aring/ thick LT-GaAs samples exhibited 1/f/sup 3/2/ noise, which was attributed to: (i) the thermal noise generated at the interface of the insulator, and (ii) the active layer due to the outdiffused metallic arsenic. Reverse gate-drain current degradation experiments were carried out at 120/spl deg/C, 160/spl deg/C, 200/spl deg/C, and 240/spl deg/C. Transconductance frequency dispersion studies were carried out before and after thermal stress on these MISFET. The transconductance of MISFET with 1000 /spl Aring/ LT-GaAs gate insulators was degraded by 40% at 100 kHz after thermal stress. The rest of the samples exhibited stable characteristics. These results indicate that composition changes had occurred at the interface in thicker LT-GaAs MISFET structures. Thinner LT-layers are ideal for achieving higher transconductance and better thermal stability without sacrificing the power capability of MISFET.

To enable the integration of organic transistors into flexible displays we have developed passive materials for a robust, layer-to-layer compatible device stack to be manufactured using a variety of industrially applicable coating and printing processes. The solution processable materials for the OSC protection and the passivation material are designed for good interlayer adhesion and OTFT stability. The 365 nm UV-curable protection layers for the OSC are compatible with fabrication processes commonly used in the display industry, e.g ., sputtering of metals. Fabrication of ink-jet printed devices is demonstrated with usage of a passive material suitable for further pixel integration. The bias stress and ambient stability was shown for the integrated stacks of transistors with the carrier mobility greater than that of amorphous silicon. We further demonstrate the development of formulations, suitable for high throughput roll-to-roll processing of soluble small molecule semiconductors allowing a high degree of structural order in the final solid film. Transistor mobility 2 /V·s is achieved with a range of viscosity values compatible with flexographic printing. Fine pattern of OSC is demonstrated with flexographic printing by adjusting the viscosity of the formulation. Uniform layers are achieved with coating and printing techniques and uniformity values are sufficient for display application.

We report an ultraviolet photoelectron spectroscopy study of the energetics at the interface between acid oxidised carbon nanotubes and the archetypical molecular N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'biphenyl-4,4'diamine(TPD). Electrical equilibrium is achieved across both interfaces within the experiment time frame due to the formation of an interfacial dipole layer which abruptly shifts the vacuum level at the interface. To the authors knowledge this is the first reported measurement of the electronic structure of a carbon nanotube / organic semiconductor interface; a system in which the magnitude of the dipole layer formed at the interface upon contact formation is proportional to the difference in work function between the substrate and organic semiconductor overlayer.

For efficient hole-extraction in solution processed organic solar cells the transparent indium-tin oxide (ITO) electrode is invariably pre-coated with a thin layer of the high work function conducting polymer poly(3,4-ethylenedioxythiophene) doped with poly(styrene-sulfonate). Herein we show that thin films of partially oxidised multi-wall and single-wall carbon nanotubes are equally effective at facilitating hole-extraction in efficient (similar to 2.7%) bulk-heterojunction organic solar cells based on poly(3-hexylthiophene) (P3HT): [6,6]-phenyl-C-61 butyric acid methyl ester (PCBM) blends. Crucially, in contrast to PEDOT:PSS, deposition is from aqueous solutions of low acidity (pH 6-7) ensuring compatibility with ITO and other emerging conducting oxides. Furthermore, thin oxidised carbon nanotube films offer greater transparency in the near-infrared as compared to PEDOT:PSS films of comparable thickness. The functionality of these nano-structured films is demonstrated in relatively large area devices (similar to 0.35 cm(2)) and the performance rationalised based on measurements of the electronic structure and morphology. (C) 2009 Elsevier B.V. All rights reserved.

A high performance semitransparent cathode is one of the major impediments to the high performance semitransparent and tandem organic photovoltaic (OPV) cells. In this work, we discuss the possible designs of semitransparent cathode to improve the performance of semitransparent OPV cells. The optical properties of the poly(3-hexylthiophene) (P3HT): 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 (PCBM)-based OPV cells were studied by the optical admittance analysis. The performance of the OPV cells made with an opaque Ca(10nm)/Ag(100nm) cathode and a semitransparent Ca(10nm)/Ag(10nm)/ITO cathode are discussed. The interfacial properties at the cathode/organic interface were analyzed using the time-of-flight secondary ion mass spectroscopy (TOF-SIMS). The TOF-SIMS depth profile revealed that calcium oxide formed at the Ca/organic interface in semitransparent OPV cells, which was induced by the ITO sputtering process. It shows that the presence of calcium oxide at the organic/cathode interface could be the main reason resulting in a poor fill factor of a semitransparent OPV cell (∼23%) as compared to that of a reference cell (∼43%).

Despite many separate studies of the two dominant defects, i.e., As precipitates and arsenic‐antisite (AsGa)‐related traps, in GaAs epilayers grown by molecular beam epitaxy at low temperatures, they are seldom examined simultaneously. In this letter, we report the detection of both defects in electron trap spectrum obtained by zero quiescent bias voltage transient current spectroscopy. The As precipitates appear as a broad continuum of states in the lower temperature region (

In this paper, the theoretical study of intersubband transitions in quantum well infrared photodetectors (QWIPs) applying the eight bands k.p model incorporated with envelope function approximation is described. The focus of the work is on the intersubband transition in n-type IIIV QWIP based on AIGaAs/GaAs and AlGaAs/InGaAs material system, with particular emphasis placed on the physics of TE excited transition and the improvement of resulted absorption. Various theoretical absorption spectra of the two material systems are compared, the distinct mechanisms of the intersubband transition for the two material systems are proposed. Possible ways of improving on the absorption for such excitation are also investigated and discussed.

The incorporation of low-temperature (LT) GaAs intermediate layers grown at 230°C had been shown to have the effects of improving the crystalline quality of GaAs epilayers on Si. The use of this LT-GaAs intermediate layer between the GaAs nucleation layer and the GaAs overlayer has improved the photoluminescence (PL) peak intensity by about five times, and reduced the GaAs (004) X-ray diffraction full width at half maximum (FWHM) by 59 arcsecs. The PL results were subsequently confirmed by cathodoluminescence images. The dominant deep level electron trap in the LT-GaAs epilayer grown on Si substrate was the same as that found in LT-GaAs epilayer grown on GaAs substrate.

We report the modification of the transport, optical and electrical properties of 200 nm thick N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'biphenyl-4,4'diamine (TPD) films on indium-tin oxide (ITO) when a low density of acid oxidized single-walled carbon nanotubes (o-SWCNTs) are present at the ITO/TPD interface. Most significantly, current-voltage measurements show strong evidence for a change from contact to bulk limited transport. We postulate that these observations result from a change in the structure of the TPD film seeded by the presence of o-SWCNTs at the ITO surface.

This letter reports our efforts to improve the power conversion efficiency (PCE) and the optical transparency of semitransparent poly(3-hexylthiophene) (P3HT):1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C60 (PCBM) based photovoltaic (PV) cells. Semitransparent P3HT:PCBM based solar cells were prepared based on parameters obtained by optical admittance analysis. The performance of structurally identical polymer PV cells made with a reflective calcium/silver cathode and a semitransparent Ca(10nm)∕Ag(10nm)/indium tin oxide cathode are compared. For semitransparent polymer PV cells with a 75nm thick active P3HT:PCBM blend layer, an average transmission of more than 30% was achieved with a high PCE of 1.7% under simulated AM1.5G illumination of 100mW∕cm2.

An aluminum-laminated polyethylene terephthalate (Al-PET) is used as the substrate for flexible organic light-emitting devices (OLEDs). The efficient flexible electroluminescent devices have a top-emitting OLED architecture. An acrylic layer is formed on the Al-PET surface to improve the surface morphology and also the adhesion between the substrate and the anode. Poly(styrene sulfonate)-doped poly(3,4-ethylene dioxythiophene) was used as hole transporting layer. The light-emitting polymer used is a phenyl-substituted poly(p-phenylenevinylene). Bilayer anodes of Ag∕CFX and Ag/indium-tin oxide and a semitransparent top cathode were used for the flexible polymer OLEDs. For a flexible polymer OLED with a 110-nm-thick light-emitting polymer, it exhibited superior electrical and optical characteristics with a luminous efficiency of 4.56cd∕A at an operating voltage of 7.5V.

Fluoropolymers are characterized by high chemical inertness and, when in solid state, by superficial dipoles due to the C–F bond where the charge density is strongly displaced. These two characteristics are exploited here for fine control of charge balance in organic light-emitting devices and for preventing electrochemical interaction between heterogeneous layers. The insertion of a thin layer of polytetrafluoroethylene, PTFE, at the interface between poly(ethylene dioxythiophene):poly(styrene sulfonic acid), PEDOT:PSS, and an electroluminescent polymer leads to improved device efficiency and longevity. The presence of the superficial dipole increases the effective work function of the anode and improves the charge balance which enhances the external quantum efficiency, EQE, of the devices by up to a factor of two without significant effects on the luminance levels. The insertion of the PTFE layer reduces the photoluminescence quenching at the PEDOT:PSS/polymer interface, however we show that the EQE enhancement is mainly due to a better confinement of minority carrier electrons in the active layer. The lifetime of the devices shows a remarkable increase correlated with the insertion of the PTFE layer. Such improvements are ascribed to the reduced electrochemical interaction between the electroluminescent polymer and PEDOT:PSS due to the chemically inert nature of PTFE. The PTFE acts as a chemical zipper of two heterogeneous media with the added functionality of control over the charge balance.