Identification of origin of insulating polymer maneuvered photoredox catalysis

Solid non-conjugated polymers have long been regarded as insulators due to deficiency of delocalizedπelectrons along the molecular chain framework.Up to date,origin of insulating polymer regulated charge transfer has not yet been uncovered.In this work,we unleash the root origin of charge transport capability of insulating polymer in photocatalysis.We ascertain that insulating polymer plays crucial roles in fine tuning of electronic structure of transition metal chalcogenides(TMCs),which mainly include altering surface electron density of TMCs for accelerating charge transport kinetics,triggering the generation of defect over TMCs for prolonging carrier lifetime,and acting as hole-trapping mediator for retarding charge recombination.These synergistic roles contribute to the charge transfer of insulating polymer.Our work opens a new vista of utilizing solid insulating polymers for maneuvering charge transfer toward solar energy conversion.

Prediction of the Aging of HTV Silicone Rubber Using Chemical Concentration and Polynomial Interpolation Approach

Predicting the lifetime of polymeric insulators is one of the most important research topics in studying the life cycle of high voltage insulators in the power transmission and distribution networks. HTV （high temperature vulcanized） silicone rubber is a high performance dielectric material used within electrical power equipment, in particular transmission and distribution insulators. In this paper, we proposed a new approach using the Newton＇s method and Lagrange method to predict the aging of HTV silicone rubber that are subjected to multiple stress conditions. Concentration of chemical elements such as carbon, oxygen, silicon and aluminum were obtained and evaluated using a SEM （scanning electron microscope） with EDS （energy dispersive X-ray spectroscopy）. Curve fitting using the Newton＇s and Lagrange interpolation methods yield useful linear interpolation equations that describe the aging characteristic of the specimens under study. This approach can be applied to predict the change in chemical concentration of polymeric insulators over the life cycle with good accuracy.

High T_(g) Polymer Insulator Yields Organic Photovoltaic Blends with Superior Thermal Stability at 150℃

Record-breaking organic solar cells(OSCs)based on blends of polymer donors and small molecule acceptors often show undesirable degradati on,which severely precludes their practical use.Herei n,we demonstrate a facile and cost-effective approach to con struct thermally stable OSCs at 150℃ by incorporating a small amount of a polymer insulator polyacenaphthylene(PAC)with high glass-transition temperature over 230℃ into polymer:acceptor blends.The model PTB7-Th:EH-IDTBR blend with 10 wt%PAC maintained above 85%of its initial efficiency upon continuous heating at 150℃ for over 800 h,while the efficiency of the blend without PAC sharply dropped by 70%after-300 h.Owing to high miscibility with acceptors,PAC confines the motion of the acceptor molecules and suppresses the acceptor crystallization at elevated temperatures,leading to significantly improved stability.Importantly,the effectiveness of this blending approach was also validated in many other OSC systems,showing great potential for achieving high-performance thermally stable electronics.

Research progress on space charge characteristics in polymeric insulation

Due to their excellent electrical insulation properties and processability,polymer materials are used in many electrical products.It is widely believed that space charge plays an important role for the electric field distribution,conduction,ageing,and electric breakdown of polymeric insulation.This paper reviews measurements and characteristics of space charge behavior which mainly determined by the pulsed electro-acoustic(PEA)measurement technique.Particular interests are the effects of the applied voltage,the electrodes,temperature,humidity,microstructure,additives,and filler materials on accumulation,distribution,transport,and the decay of space charge in polymeric materials.This review paper is to provide an overview on various space charge effects under different conditions,and also to summarize the information for polymeric materials with suppressed space charge and improved electrical behavior.

Thermal reliability analysis and optimization of polymer insulating through-silicon-vias(TSVs) for 3D integration

Polymer insulating through-silicon-vias （TSVs） is an attractive approach for high-performance 3D integration systems. To further demonstrate the polymer insulating TSVs, this paper investigates the thermal stability by measuring the leakage current under bias-temperature condition, studies the thermal stress characteristics with Finite Element Analysis （FEA）, and tries to improve the thermal mechanical reliability of high-density TSVs array by optimizing the geometry parameters of pitch, liner and redistribution layer （RDL）. The electrical measurements show the polymer insulating TSVs can maintain good insulation capability （less than 2x 10TM A） under challenging bias-temperature conditions of 20 V and 200~C, despite the leakage degra- dation observation. The FEA results show that the thermal stress is significantly reduced at the sidewall, but highly concen- trates at the surface, which is the potential location of mechanical failure. And, the analysis results indicate that the polymer insulating TSVs （diameter of 10 μm, depth of 50 μm） array with a pitch of 20 μm, liner thickness of 1 μm and RDL radius of 9 μm has an optimized thermal-mechanical reliability for application.