Зависимость электрической проводимости никель-саленовых полимеров от напряжения затвор-исток в электрохимическом транзисторе

For the first time, polymeric forms of the complexes N,N′-bis(salicylidene)ethylenediaminonickel(II) and N,N′-bis(3-methoxysalicylidene)ethylenediaminonickel(II) have been investigated as functional materials for the conducting channels of organic electrochemical transistors. The dependence of the electrical conductivity of the polymers on the electrolyte anion-doping level has been established. The polymer film conductivity versus gate voltage curve parameters have been shown to depend on the molecular structure of the complex and the nature of the electrolyte solvent.

Ferroelectric Ba0.75Sr0.25TiO3 tunable charge transfer in perovskite devices

Interfacial charge recombination is a main issue causing the efficiency loss of the perovskite solar cells (PSCs). Here, ferroelectric Ba0.75Sr0.25TiO3 (BST) is introduced as a polarization tunable layer to promote the interfacial charge transfer of the PSCs. The coexistence of ferroelectric polarization and charge carriers in BST is confirmed by density functional theory (DFT) calculations. Experimental characterization demonstrates the polarization reversal and the existence of domain in BST film. The BST film conductivity is tested as 2.98×10-4 S/cm, which is comparable to the TiO2 being used as the electron transporting layer (ETL) in PSCs. The calculations results prove that BST can be introduced into the PSCs and the interfacial charge transfer can be tuned by ferroelectric polarization. Thus, we fabricated the BST-based PSCs with a champion power conversion efficiency (PCE) of 19.05% after poling, which is higher for 4% than that without poling.

Study of Microwave-Induced Ag Nanowire Welding for Soft Electrode Conductivity Enhancement

Silver nanowire (AgNW)-coated thin films are widely proposed for soft electronics application due to their good conductivity, transparency and flexibility. Here, we studied the microwave welding of AgNW-based soft electrodes for conductivity enhancement. The thermal effect of the microwave to AgNWs was analyzed by dispersing the nanowires in a nonpolar solution, the temperature of which was found to be proportional with the nanowire diameters. AgNWs were then coated on a thin film and welded under microwave heating, which achieved a film conductivity enhancement of as much as 79%. A microwave overheating of AgNWs, however, fused and broke the nanowires, which increased the film resistance significantly. A soft electrode was finally demonstrated using the microwave-welded AgNW thin film, and a 1.13 µA/mM sensitivity was obtained for glucose sensing. Above all, we analyzed the microwave thermal effect on AgNWs to provide a guidance to control the nanowire welding effect, which can be used for film conductivity enhancement and applied for soft and bio-compatible electrodes.

A simple model to predict hydraulic conductivity in medium to dry soil from the water retention curve

<p>The mathematical representation of the soil hydraulic properties is of central importance for modeling water, solute and energy transport in the vadose zone. The established models of the soil water retention and hydraulic conductivity curves account for capillary water retention and capillary conductivity, but neglect water adsorption and water flow in films and in pore corners. They are therefore suited for modeling flow and transport processes in the medium to wet moisture range, but are susceptible to failure in dry soil. The model system developed by Peters (2013, 2014) and Iden and Durner (2014) (PDI in the following) is a simple parametric framework that overcomes these structural shortcomings. However, it requires an additional parameter to scale the hydraulic conductivity curve in the medium to dry moisture range where non-capillary flow is dominant. Measured conductivity data are required to estimate this scaling parameter and to compute the hydraulic conductivity over the complete moisture range. In this contribution, we first analyze the original model formulation and show that it is in close agreement with a comprehensive physically-based model for film conductivity in porous media. We then suggest a physically based method to predict the film conductivity from the water retention curve. This reduces the number of free parameters by one and gives a complete prediction of the hydraulic conductivity curve if only water retention data and the saturated conductivity are known. Application to literature data covering a broad range of textures shows a very good agreement between measured data and predictions.</p>

Conductivity Extraction Using a 180 GHz Quasi-Optical Resonator for Conductive Thin Film Deposited on Conductive Substrate

Measurement of electrical conductivity of conductive thin film deposited on a conductive substrate is important and challenging. An effective conductivity model was constructed for a bilayer structure to extract thin film conductivity from the measured Q-factor of a quasi-optical resonator. As a demonstration, aluminium films with thickness of 100 nm were evaporated on four silicon wafers whose conductivity ranges from ~101 to ~105 S/m (thus, the proposed method can be verified for a substrate with a wide range of conductivity). Measurement results at ~180 GHz show that average conductivities are 1.66 × 107 S/m (which agrees well with direct current measurements) with 6% standard deviation. The proposed method provides a contactless conductivity evaluation method for conductive thin film deposited on conductive substrate which cannot be achieved by the existing microwave resonant method.

THE CONDUCTIVITY OF SILICON MESARESISTORS IN JOULE HEATING CONDITIONS

The article presents the results on the influence of geometric factors and surface states at the interfaces on the processes of electronic transport in thin silicon films on dielectric. TCAD Sentaurus calculations of the mesaresistors relative change resistance (ΔR\R) on the applied power, have shown the decisive role of traps with "shallow" states in the film conductivity. Their presence leads to a nonmonotonic dependence ΔR\R.