Effects of solvent additive on inverted structure PCPDTBT:PC71BM bulk heterojunction organic solar cells
This work investigates the effects of the solvent additive, 1,8‐octanedithiol (1,8‐ODT), on solution‐processed inverted bulk heterojunction (BHJ) organic solar cells based on a thin film blend of poly[2,1,3‐benzothiadiazole‐4,7‐diyl[4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b:3,4‐b′]dithiophene‐2,6‐diyl]] (PCPDTBT) and [6,6]‐phenyl C71 butyric acid methyl ester (PC71BM). In this work, varying concentrations of 1,8‐ODT were added into the polymer solution in order to optimise the device performance. The UV–Vis spectrometer measurements showed that adding 1,8‐ODT can improve the magnitude of light absorption in the blend film, as well as inducing an ∼40 nm red shift for long wavelengths. External quantum efficiency (EQE) measurements displayed improvements at all wavelengths for 1–4 vol% 1,8‐ODT concentration, when compared to the reference device. Current density–voltage (J–V) measurements confirmed this addition of photocurrent, as the short circuit current density (Jsc) increases by 23%, from 9.89 mA cm−2 for the reference to 12.14 mA cm−2 for the 1 vol% additive cell. The highest average device efficiency of 2.59% was obtained using a 1,8‐ODT concentration of 3 vol%. Further increasing additive concentration caused a reduction in efficiency. Additionally, the effect of drying the additive processed films in a vacuum was investigated. Drying in a vacuum had little effect on films processed with low additive concentration. However, the vacuum drying process led to a significant efficiency enhancement for high 1,8‐ODT concentrations. The efficiency of the 4 vol% 1,8‐ODT devices increased by 25% as a result of drying in a vacuum. This was due to the removal of excess residual additive from the active layer.
Congenital myasthenic syndromes (CMS) are heterogeneous disorders in which the safety margin of neuromuscular transmission is impaired by one or more specific mechanisms. Since the advent of next‐generation sequencing methods, the discovery of novel CMS targets and phenotypes ha ... more
Myasthenia gravis (MG) with antibodies to muscle‐specific kinase (MuSK) is characterized by fluctuating fatigable weakness. In MuSK MG, involvement of bulbar muscles, neck, and shoulder and respiratory weakness are more prominent than in acetylcholine receptor (AChR) MG. MuSK au ... more
Because of the failure of many promising therapeutics identified in preclinical evaluation, funding sources have established guidelines for increased rigor in animal evaluations. The myasthenia gravis (MG) community of scientists has developed guidelines for preclinical assessme ... more
Smart skin that can respond to external stimuli could have important applications in medicine and robotics. Using only items found in a typical household, researchers have created multi-sensor artificial skin that's capable of sensing pressure, temperature, humidity, proximity, pH, and air ... more
Mercury contamination in water and on land is of worldwide concern due to its toxic effects on ecosystems and human health. Mercury toxicity is of particular concern to reptiles because they are currently experiencing population declines. Also, reptiles are ideal indicators of mercury conta ... more
A team of pioneering South Korean scientists have succeeded in producing the polymers used for everyday plastics through bioengineering, rather than through the use of fossil fuel based chemicals. This groundbreaking research, which may now allow for the production of environmentally consci ... more