Recent progresses on solution-processed silver nanowire based transparent conducting electrodes for organic solar cells

Organic photovoltaics (OPVs) are considered as a future alternative for conventional silicon based solar cells, owing to their low cost, ease of production and high-throughput. The transparent conducting electrode (TCE) is a fundamental component of OPVs. Traditionally, indium tin oxide (ITO) has been mainly utilized as a TCE in OPV applications due to its relatively high transparency and low sheet resistance. However, increasing demand for the optoelectronic devices has led to large fluctuations in ITO prices in the past decade and ITO is known to account more than 50% of the total cost of OPV devices. Thus, it is believed that development of solution-processable alternative materials is of great importance in reducing the cost of OPVs. Numerous materials, including silver nanowires, carbon nanotubes, graphene and conducting polymers, have been offered as replacements for ITO. This article reviews recent progress on fabrication of TCE via solution based coating techniques of silver nanowires (Ag NWs). In addition, performance of the Ag NWs based TCE in OPVs is summarized. Finally, we explore the future outlook for Ag NWs based TCE at the end of the review.     

Sonication-assisted layer-by-layer deposition of gold nanoparticles for highly conductive gold patterns

Sonication-assisted layer-by-layer (LBL) deposition of gold nanoparticles (GNPs) was carried out in an attempt to prepare highly conductive gold patterns on polyimide substrates. First, sonication time was optimized with GNPs (12.8 nm) whose size was large enough to be analyzed by FE-SEM in order to evaluate the surface coverage. Next, multilayer formation (4, 8 and 12 layer) was confirmed using ethanedithiol (EDT) as linker molecules under optimized conditions by measuring their UV absorption, near-IR (NIR) transmittance, thickness, and electrical conductivity. Finally, 20-layer films using small GNPs (2.5 nm) were prepared with or without patterning, followed by sintering at 150 °C for 1 h, which provided clean gold patterns with high electrical conductivity (2.5 × 10⁵ Ω⁻¹ cm⁻¹).     

New and clean synthesis of N-substituted pyrroles under microwave irradiation

N-Substituted homochiral pyrrole derivatives were synthesized by the ring-closure reaction of cis-1,4-dichloro-2-butene with various amine compounds on a silica surface under microwave irradiation.     

On Some New Generalized Difference Sequence Spaces

Let (x) = A(x) , where A(x) denotes the number of square-full integers not exceeding x. In this paper, we prove that (x) = O , which improves the exponent 4/27 obtained by Y.-C. Cai [5].     

Specific energy based rippability classification system for coal measure rock

Specific energy is simply defined as the work done per unit volume of rock excavated. Specific energy is an important performance parameter as it relates cutting force to the amount of rock excavated. In this paper the development of a new rippability classification system for coal measure rock based on specific energy is presented. Extensive field and laboratory studies were conducted at six different lignite open pit mines and rock mechanics laboratory. Since both ground and machine properties are incorporated, the rippability classes of rocks and the approximate hourly ripper productions of different dozer types can be assessed by using the developed system.     

Electrochemical properties of PP membranes with plasma polymer coatings of acrylic acid

Commercial polypropylene (PP) membranes were modified by plasma polymerization coating of acrylic acid, in combination with oxygen flow or oxygen plasma etching. First, conditions for plasma polymerization coating were optimized in terms of the chemical resistance of the coatings and their ion exchange capacity as a function of plasma power, internal pressure and treatment time. Next, the plasma polymerization coating of acrylic acid was combined with oxygen flow or oxygen plasma etching, and their conditions were also optimized by measuring the ion exchange capacity. Finally, the modified membranes were subjected to electrical resistance and transport number measurements and characterized by -step, FT-IR/ATR and SEM. Among the modification methods, oxygen plasma etching followed by the plasma polymerization coating of acrylic acid provided the best electrochemical properties with 1.75 meq/g (IEC) and 112 Ω cm² (ER), 0.88 (TN).