Spectral Splitting Solar Cells Consisting of a Mesoscopic Wide-Bandgap Perovskite Solar Cell and an Inverted Narrow-Bandgap Perovskite Solar Cell.

In comparison to monolithic perovskite/perovskite double-junction solar cells, a four-terminal spectrum-splitting system is a simple method to obtain a higher power conversion efficiency (PCE) because it has no constraints of unifying the structures of the top and bottom cells. In this work, utilizing the fact that low-bandgap Sn-Pb bottom cells work the best in p-i-n while Pb-based wide-bandgap top cells work better in an n-i-p architecture, a wide-bandgap (Eg = 1.61 eV) perovskite solar cell with a mesoscopic structure and a narrow-bandgap (Eg = 1.27 eV) perovskite solar cell with an inverted structure were combined to fabricate a double-junction four-terminal spectral splitting solar cell. The double-junction solar cell with the 801 nm spectral splitting with an active area of 0.18 cm2 was found to work with a PCE of 25.3%, which is the highest reported so far for a 4-T all-perovskite double-junction spectral splitting solar cell.

Screen-Printable Silver Paste Material for Semitransparent and Flexible Metal-Semiconductor-Metal Photodetectors with Liquid-Phase Procedure.

Photodetectors are widely applied in modern industrial fields because they convert light energy into electrical signals. We propose a printable silver (Ag) paste electrode for a highly flexible metal-semiconductor-metal (MSM) broadband visible light photodetector as a wearable and portable device. Single-crystal and surface-textured silicon substrates with thicknesses of 37.21 µm were fabricated using a wet etching process. Surface texturization on flexible Si substrates enhances the light-trapping effect and minimizes reflectance from the incident light, and the average reflectance is reduced by 16.3% with pyramid-like structures. In this study, semitransparent, conductive Ag paste electrodes were manufactured using a screen-printing with liquid-phase process to form a flexible MSM broadband visible light photodetector. The transmittance of the homemade Ag paste solution fell between 34.83% and 36.98% in the wavelength range of visible light, from 400 nm to 800 nm. The highest visible light photosensitivity was 1.75 × 104 at 19.5 W/m2. The photocurrents of the flexible MSM broadband visible light photodetector were slightly changed under concave and convex conditions, displaying stable and durable bending properties.

Trivalent Cations Detection of Magnetic-Sensitive Microcapsules by Controlled-Release Fluorescence Off-On Sensor.

A pyrene-based derivative, 2-((pyrene-1-ylmethylene)amino)ethanol (PE) nanoparticle, was encapsulated via water-in-oil-in-water (W/O/W) double emulsion with the solvent evaporation method by one-pot reaction and utilized as a fluorescence turn-on sensor for detecting Fe3+, Cr3+, and Al3+ ions. Magnetic nanoparticles (MNPs) embedded in polycaprolactone (PCL) were used as the magnetic-sensitive polyelectrolyte microcapsule-triggered elements in the construction of the polymer matrix. The microcapsules were characterized by ultraviolet-visible (UV-Vis) and photoluminescence (PL) titrations, quantum yield (Φf) calculations, 1H nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and superconducting quantum interference device magnetometry (SQUID) studies. This novel responsive release of the microcapsule fluorescence of the turn-on sensor for detecting trivalent cations was due to the compound PE and the MNPs being incorporated well within the whole system, and an effective thermal and kinetic energy transfer between the core and shell structure efficiently occurred in the externally oscillating magnetic field. The magnetic-sensitive fluorescence turn-on microcapsules show potential for effective metal ion sensing in environmental monitoring and even biomedical applications. Under the optimal controlled-release probe fluorescence conditions with high-frequency magnetic field treatment, the limit of detection (LOD) reached 1.574-2.860 µM and recoveries ranged from 94.7-99.4% for those metals in tap water.

Use of curcumin-modified diamond nanoparticles in cellular imaging and the distinct ratiometric detection of Mg2+/Mn2+ ions.

An intrinsically luminescent curcumin-modified nanodiamond derivative (ND-Cur) has been synthesized as an effective probe for cell imaging and sensory applications. DLS data allowed the particle size of ND-Cur to be estimated (170.6 ± 46.8 nm) and the zeta potential to be determined. The photoluminescence signal of ND-Cur was observed at 536 nm, with diverse intensities at excitation wavelengths of 350 to 450 nm, producing yellow emission with a quantum yield (Φ) of 0.06. Notably, the results of the MTT assay and cell imaging experiments showed the low toxicity and biocompatibility of ND-Cur. Subsequently, investigations of the selectivity towards Mg2+ and Mn2+ ions were performed by measuring intense fluorescence peak shifts and "Turn-off" responses, respectively. In the presence of Mg2+, the fluorescence peak (536 nm) was shifted and then displayed two diverse peaks at 498 and 476 nm. On the other hand, for Mn2+ ions, ND-Cur revealed a fluorescence-quenching response at 536 nm. Fluorescence studies indicated that the nanomolar level detection limits (LODs) of Mg2+ and Mn2+ ions were approximately 423 and 367 nM, respectively. The sensing mechanism, ratiometric changes and binding site were established through PL, FTIR, Raman, SEM, TEM, DLS and zeta potential analyses. Furthermore, the effective determination of Mg2+ and Mn2+ ions by ND-Cur has been validated through cell imaging experiments.

A Sodium Chloride Modification of SnO2 Electron Transport Layers to Enhance the Performance of Perovskite Solar Cells.

A sodium chloride modification was applied where different amounts of sodium chloride was physically blended in a tin oxide colloid solution to passivate the interface between the electron transport layer (ETL) and perovskite layer and improve the performance of perovskite solar cells. Sodium chloride-modified tin oxide was utilized as the electron transport material to fabricate perovskite solar cells. It was found that sodium chloride-modified tin oxide as an ETL could considerably enhance the performance of the device compared to pristine tin oxide. The power conversion efficiency of the perovskite solar cell displayed 8.8% remarkable improvement from 18.7 ± 0.4% to 20.3 ± 0.3% on average and 9.5% improvement from 18.9 to 20.7% in champion devices because of the considerable enhancement of the fill factor when 25 mM sodium chloride-modified tin oxide as the ETL was used in comparison with pristine tin oxide.

The Multifunctionally Graded System for a Controlled Size Effect on Iron Oxide-Gold Based Core-Shell Nanoparticles.

We report that Fe3O4@Au core-shell nanoparticles (NPs) serve as a multifunctional molecule delivery platform. This platform is also suitable for sensing the doxorubicin (DOX) through DNA hybridization, and the amount of carried DOX molecules was determined by size-dependent Fe3O4@Au NPs. The limits of detection (LODs) for DOX was found to be 1.839 nM. In our approach, an Au nano-shell coating was coupled with a specially designed DNA sequence using thiol bonding. By means of a high-frequency magnetic field (HFMF), a high release percentage of such a molecule could be efficiently achieved in a relatively short period of time. Furthermore, the thickness increase of the Au nano-shell affords Fe3O4@Au NPs with a larger surface area and a smaller temperature increment due to shielding effects from magnetic field. The change of magnetic property may enable the developed Fe3O4@Au-dsDNA/DOX NPs to be used as future nanocarrier material. More importantly, the core-shell NP structures were demonstrated to act as a controllable and efficient factor for molecule delivery.

Eco-Friendly and Biodegradable Biopolymer Chitosan/Y2O3 Composite Materials in Flexible Organic Thin-Film Transistors.

The waste from semiconductor manufacturing processes causes serious pollution to the environment. In this work, a non-toxic material was developed under room temperature conditions for the fabrication of green electronics. Flexible organic thin-film transistors (OTFTs) on plastic substrates are increasingly in demand due to their high visible transmission and small size for use as displays and wearable devices. This work investigates and analyzes the structured formation of aqueous solutions of the non-toxic and biodegradable biopolymer, chitosan, blended with high-k-value, non-toxic, and biocompatible Y2O3 nanoparticles. Chitosan thin films blended with Y2O3 nanoparticles were adopted as the gate dielectric thin film in OTFTs, and an improvement in the dielectric properties and pinholes was observed. Meanwhile, the on/off current ratio was increased by 100 times, and a low leakage current was observed. In general, the blended chitosan/Y2O3 thin films used as the gate dielectric of OTFTs are non-toxic, environmentally friendly, and operate at low voltages. These OTFTs can be used on surfaces with different curvature radii because of their flexibility.

A flexible and miniaturized hair dye based photodetector via chemiluminescence pathway.

A flexible and miniaturized metal semiconductor metal (MSM) biomolecular photodetector was developed as the core photocurrent system through chemiluminescence for hydrogen peroxide sensing. The flexible photocurrent sensing system was manufactured on a 30-µm-thick crystalline silicon chip by chemical etching process, which produced a flexible silicon chip. A surface texturization design on the flexible device enhanced the light-trapping effect and minimized reflectivity losses from the incident light. The model protein streptavidin bound to horseradish peroxidase (HRP) was successfully immobilized onto the sensor surface through high-affinity conjugation with biotin. The luminescence reaction occurred with luminol, hydrogen peroxide and HRP enzyme, and the emission of light from the catalytic reaction was detected by underlying flexible photodetector. The chemiluminescence in the miniaturized photocurrent sensing system was successfully used to determine the hydrogen peroxide concentration in real-time analyses. The hydrogen peroxide detection limit of the flexible MSM photodetector was 2.47mM. The performance of the flexible MSM photodetector maintained high stability under bending at various bending radii. Moreover, for concave bending, a significant improvement in detection signal intensity (14.5% enhancement compared with a flat configuration) was observed because of the increased photocurrent, which was attributed to enhancement of light trapping. Additionally, this detector was used to detect hydrogen peroxide concentrations in commercial hair dye products, which is a significant issue in the healthcare field. The development of this novel, flexible and miniaturized MSM biomolecular photodetector with excellent mechanical flexibility and high sensitivity demonstrates the applicability of this approach to future wearable sensor development efforts.

Ventricular septal rupture after early successful thrombolytic therapy in acute myocardial infarction: a case report.

Ventricular septal defect (VSD) is a severe complication of acute myocardial infarction and has a high mortality rate. This complication appears to have declined in the reperfusion era. It has mostly been reported in elderly or female patients who suffer from anterior wall infarction, patients with multivessel coronary artery disease (CAD) or occluded infarct-related artery (IRA) without collateral circulation, or patients who have had delayed reperfusion therapy. Here, we report the case of a 60-year-old male patient who presented with persistent chest pain and Killip I ST-segment-elevation myocardial infarction. Thrombolytic therapy was started 3 hours after the onset of chest pain. Based on the subsidence of chest pain, resolution of the elevated ST segment, and early peak of cardiac enzymes, reperfusion was thought to be successful. However, on the third day of admission, the patient complained of dyspnea after defecation and was found to have new-onset grade 3 pansystolic murmur over the left sternal border. Cardiac echography showed an apical VSD. A Swan-Ganz catheter was inserted into the right side of the heart; analysis of blood oxygen saturation revealed a 6% step-up of oxygen in the right ventricle. Coronary angiography showed only one-vessel CAD and TIMI 3 flow in the IRA. The patient received intensive medical management and underwent VSD repair and internal mammary artery bypass grafting to the left anterior descending artery. His recovery was uneventful. This case illustrates that VSD can be found in patients receiving early successful reperfusion therapy, with one-vessel CAD, and TIMI 3 flow in the IRA.