Large-Area Nonfullerene Organic Photovoltaic Modules with a High Certified Power Conversion Efficiency.

Achieving large-area organic photovoltaic (OPV) modules with reasonable cost and performance is an important step toward commercialization. In this work, solution-processed conventional and inverted OPV modules with an area of 216 cm were fabricated by the blade coating method. Film uniformity was controlled by adjusting the fabrication parameters of the blade coating procedure.

Facile Fabrication of a Bio-Inspired Leaf Vein-Based Ultra-Sensitive Humidity Sensor with a Hygroscopic Polymer.

Bio-inspired materials have received significant interest in the development of flexible electronics due to their natural grid structures, especially natural leaf vein networks. In this work, a bio-inspired leaf vein-based flexible humidity sensor is demonstrated. The proposed sensor is composed of a leaf/Al/glycerin/Ag paste.

Rapid quality test for drinking water by vertical-channel organic semiconductor gas sensor.

In this work, we proposed a rapid and easy check of the drinking water pollution level due to bacteria growth by semiconductor gas sensor. Highly sensitive vertical channel organic ammonia gas sensor was used to detect the gases emitted from the polluted water, and then determined effective ammonia concentration according to its response. Residues from meat of fish, shrimp, and fruits were mashed and added to the clean water.

Solution-Processed Chloroaluminum Phthalocyanine (ClAlPc) Ammonia Gas Sensor with Vertical Organic Porous Diodes.

In this research work, the gas sensing properties of halogenated chloroaluminum phthalocyanine (ClAlPc) thin films were studied at room temperature. We fabricated an air-stable ClAlPc gas sensor based on a vertical organic diode (VOD) with a porous top electrode by the solution process method. The surface morphology of the solution-processed ClAlPc thin film was examined by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM).

Stable and Reversible Photoluminescence from GaN Nanowires in Solution Tuning by Ionic Concentration.

We report response of photoluminescence (PL) from GaN nanowires without protection in solutions. The distinct response is not only toward pH but toward ionic concentration under same pH. The nanowires appear to be highly stable under aqueous solution with high ionic concentration and low pH value down to 1.

Breath Ammonia Is a Useful Biomarker Predicting Kidney Function in Chronic Kidney Disease Patients.

Chronic kidney disease (CKD) is a public health problem and its prevalence has increased worldwide; patients are commonly unaware of the condition. The present study aimed to investigate whether exhaled breath ammonia via vertical-channel organic semiconductor (V-OSC) sensor measurement could be used for rapid CKD screening. We enrolled 121 CKD stage 1-5 patients, including 19 stage 1 patients, 26 stage 2 patients, 38 stage 3 patients, 21 stage 4 patients, and 17 stage 5 patients, from July 2019 to January 2020.

A Cylindrical Ion Sensor Tip with a Diameter of 1.5 mm for Potentially Invasive Medical Application.

A fine cylindrical chemical sensor tip is developed with optical fiber in the core, surrounded by a transparent cylinder of photopolymer Norland Optical Adhesive 61 (NOA 61), and covered by a polymer hydrogel mixed with sensing molecules. The overall diameter is as small as 1.5 mm.

Visible light positioning (VLP) system using low-cost organic photovoltaic cell (OPVC) for low illumination environments.

We propose and demonstrate a received-signal-strength (RSS) based visible light positioning (VLP) system using a low-cost organic photovoltaic cell (OPVC) receiver (Rx). The OPVC is a passive device without the need of external power supply. It could detect VLC signal and harvest energy.

The influence of the interfacial layer on the stability of all-solution-processed organic light-emitting diodes.

Improving the stability of large-area organic light-emitting diodes is very important for practical applications. The interfacial layer plays a crucial role to improve the electron injection characteristic. In this work, devices prepared by various solution-processed interfacial materials and thermal-evaporated CsF were compared.

Near-Infrared Laser-Annealed IZO Flexible Device as a Sensitive HS Sensor at Room Temperature.

A metal-oxide material (indium zinc oxide [IZO]) device with near-infrared (NIR) laser annealing was demonstrated on both glass and bendable plastic substrates (polycarbonate, polyethylene, and polyethylene terephthalate). After only 60 s, the sheet resistance of IZO films annealed with a laser was comparable to that of thermal-annealed devices at temperatures in the range of 200-300 °C (1 h). XPS, ATR, and AFM were used to investigate the changes in the sheet resistance and correlate them to the composition and morphology of the thin film.

Correlation between breath ammonia and blood urea nitrogen levels in chronic kidney disease and dialysis patients.

Previous studies have shown that breath ammonia (breath-NH) concentration is associated with blood urea nitrogen (BUN) levels. However, interindividual variations in breath-NH concentrations were observed. Thus, the present study aimed to assess the effect of oral cavity conditions on breath-NH concentration and to validate whether the measurement of breath-NH concentration is feasible in clinical settings.

All-Solution-Processed Red and Orange-Red Organic Light-Emitting Diodes with High-Efficiencies: The Effect of Mixed-Host Emissive Layers and Thermal Annealing Treatment.

The instability of the organic light-emitting diodes (OLEDs) during operation can be attributed to the existence of point defects on the organic layers. In this work, the effect of mixed-host emissive layer and the thermal annealing treatment were investigated to eliminate defects and to boost the device performance. The mixed-host system includes 4,4',4''-tri (9-carbazoyl) triphenylamine (TCTA) and 2,7-bis(diphenylphosphoryl)-9, 9'-spirobi[fluorene] (SPPO13).

Surface Micro-/Nanotextured Hybrid PEDOT:PSS-Silicon Photovoltaic Cells Employing Kirigami Graphene.

Kirigami graphene allows a two-dimensional material to transform into a three-dimensional structure, which constitutes an effective transparent electrode candidate for photovoltaic (PV) cells having a surface texture. The surface texture of an inverted pyramid was fabricated on a Si substrate using photolithography and wet etching, followed by metal-assisted chemical etching to obtain silicon nanowires on the surface of the inverted pyramid. Kirigami graphene with a cross-pattern array was prepared using photolithography and plasma etching on a copper foil.

Leakage-free solution-processed organic light-emitting diode using a ternary host with single-diode emission area up to 6 × 11.5 cm.

The electrical current leakage and stability are studied for solution-processed OLEDs with areas of 4.45 mm, 3 × 3.2 cm, and 6 × 11.

A low-cost, portable and easy-operated salivary urea sensor for point-of-care application.

Salivary urea was reported to be a useful biomarker to reflect the blood urea nitrogen in chronic kidney disease patients. However, as a new biomarker, enormous clinical trials are required to define the intended-use and to verify the specification. In this report, we demonstrated a low-cost easy-operated real-time sensing system (optical fiber-urea-sensing, OFUS, system) to detect salivary urea.

A Versatile Method to Enhance the Operational Current of Air-Stable Organic Gas Sensor for Monitoring of Breath Ammonia in Hemodialysis Patients.

Point-of-care (POC) application for monitoring of breath ammonia (BA) in hemodialysis (HD) patients has emerged as a promising noninvasive health monitoring approach. In this context, many organic gas sensors have been reported for BA detection. However, one of the major challenges for its integration with affordable household POC application is to achieve stable performance for accuracy and high operational current at low voltage for low-cost read-out circuitry.

Thermally Stable High-Performance Polymer Solar Cells Enabled by Interfacial Engineering.

Interfacial engineering plays an important role in determining the performance and stability of polymer solar cells (PSCs). In this study, thermally stable highly efficient PSCs are fabricated by incorporating a solution-processed cathode interfacial layer (CIL), including 4,4'-({[methyl(4-sulfonatobutyl)ammonio]bis(propane-3,1-diyl)}bis(dimethylammoniumdiyl))bis(butane-1-sulfonate) (MSAPBS) and polyethylenimine (PEI). For PSCs based on blends of poly{4,8-bis[5-(2-ethylhexyl)thiophen-2-yl]benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-[4-(2-ethylhexyl)-3fluorothieno[3,4-b]thiophene-2-carboxylate-2,6-diyl]} (PBDTTT-EFT) and [6,6]-phenyl C -butyric acid methyl ester (PC BM), the maximum power conversion efficiency (PCE) of inverted PSCs reaches 8.

Organic Gas Sensor with an Improved Lifetime for Detecting Breath Ammonia in Hemodialysis Patients.

In this work, a TFB (poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-s-butylphenyl)diphenylamine)]) sensor with a cylindrical nanopore structure exhibits a high sensitivity to ammonia in ppb-regime. The lifetime and sensitivity of the TFB sensor were studied and compared to those of P3HT (poly(3-hexylthiophene)), NPB (N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine), and TAPC (4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl) benzenamine]) sensors with the same cylindrical nanopore structures. The TFB sensor outstands the others in sensitivity and lifetime and it shows a sensing response (current variation ratio) of 13% to 100 ppb ammonia after 64 days of storage in air.

Fabrication of Flexible White Light-Emitting Diodes from Photoluminescent Polymer Materials with Excellent Color Quality.

This study developed flexible light-emitting diodes (LEDs) with warm white and neutral white light. A simple ultraviolet flip-chip sticking process was adopted for the pumping source and combined with polymer and quantum dot (QD) films technology to yield white light. The polymer-blended flexible LEDs exhibited higher luminous efficiency than the QD-blended flexible LEDs.

One-Minute Fish Freshness Evaluation by Testing the Volatile Amine Gas with an Ultrasensitive Porous-Electrode-Capped Organic Gas Sensor System.

In this work, we successfully demonstrate a fast method to determine the fish freshness by using a sensing system containing an ultrasensitive amine gas sensor to detect the volatile amine gas from the raw fish meat. When traditional titration method takes 4 h and complicated steps to test the total volatile basic nitrogen (TVB-N) as a worldwide standard for fish freshness, our sensor takes 1 min to deliver an electrical sensing response that is highly correlated with the TVB-N value. When detecting a fresh fish with a TVB-N as 18 mg/100 g, the sensor delivers an effective ammonia concentration as 100 ppb.

Toward Long-Term Stable and Efficient Large-Area Organic Solar Cells.

Here, we report that long-term stable and efficient organic solar cells (OSCs) can be obtained through the following strategies: i) combination of rapid-drying blade-coating deposition with an appropriate thermal annealing treatment to obtain an optimized morphology of the active layer; ii) insertion of interfacial layers to optimize the interfacial properties. The resulting devices based on poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-2-carboxylate-2,6-diyl)] (PBDTTT-EFT):[6,6]-phenyl C butyric acid methyl ester (PC BM) blend as the active layer exhibits a power conversion efficiency (PCE) up to 9.57 %, which represents the highest efficiency ever reported for blade-coated OSCs.

Rear interface engineering of hybrid organic-silicon nanowire solar cells via blade coating.

In this work, we investigate blade-coated organic interlayers at the rear surface of hybrid organic-silicon photovoltaics based on two small molecules: Tris(8-hydroxyquinolinato) aluminium (Alq(3)) and 1,3-bis(2-(4-tert-butylphenyl)-1,3,4-oxadiazol-5-yl) benzene (OXD-7). In particular, soluble Alq(3) resulting in a uniform thin film with a root-mean-square roughness < 0.2nm is demonstrated for the first time.

Large-Area Nano-patterning and Fabrication of Vertical Transistor Array by Non-close-packed Polystyrene Spheres.

We demonstrated a large-area nanopatterning technique with the help of a non-close-packed PS sphere layer over a large-area substrate. The non-close-packed PS sphere layer is fabricated by blade coating method. It was demonstrated that non-close-packed PS spheres can be achieved within an area of 18 cm × 25 cm on a rigid glass substrate and within an area of 10 cm × 10 cm on a flexible substrate.

Efficient hybrid white light-emitting diodes by organic-inorganic materials at different CCT from 3000K to 9000K.

The hybrid white light-emitting didoes (LED) with polyfluoren (PFO) polymer and quantum dot (QD) was investigated using dispensing method at the different correlated color temperature (CCT) for cool and warm color temperature. This result indicates that the hybrid white LED device has the higher luminous efficiency than the convention one, which could be attributed to the increased utilization rate of the UV light. Furthermore, the CIE 1931 coordinate of high quality white hybrid LED with different CCT range from 3000K to 9000K is demonstrated.