Solution-processed Molybdenum Oxide Hole Transport Layer Stabilizes Organic Solar Cells

The hole transport layer(HTL)affects the device performance and stability of organic solar cells.In this work,a stable molybdenum oxide(MoO_(x))hole transport layer with low cost was prepared by adjusting the state of the precursor solution with an alcoholic solution of molybdenum acetylacetonate through an oxidant.The MoO_(x) transport layer has good transmittance with a work function of 5.07 eV and higher surface energy.The PM6:Y6 devices using MoO_(x) HTL achieve a high efficiency of 16.8%.MoO_(x) HTL exhibits good applicability with excellent performance in both ternary and all-polymer systems.Air storage stability T80 of the all-polymer device using MoO_(x) HTL was over 600 h,much higher than 70 h of the PEDOT:PSS-based device,and its thermal stability at 85℃ and operational stability under light show better stability than that of the PEDOT:PSS hole transport layer.This work provides a facile and low-cost method to fabricate HTL for organic solar cells,which is beneficial to improve their efficiency and stability.

Synthesis and application of green solvent dispersed organic semiconducting nanoparticles

Organic photovoltaic semiconductors have made significant progress and have promising application prospects after decades of development.When compared with traditional semiconductors,the solution method for preparing photovoltaic semiconductors shows the advantages of low cost and convenient preparation.However,because of the extremely poor solubility of the polymers used to prepare semiconductors,toxic solvents must be used when using the solution method,which has significant negative effects on the environment and operators and severely limits its development prospects.Organic nanoparticles(NPs),on the other hand,can avoid these issues.Because NPs are typically water or alcohol-based,no toxic solvents are used.Furthermore,NPs have been used in organic solar cells,hydrogen catalysis,organic light-emitting diodes,and other fields after nearly two decades of development,and their preparation methods have been developed.We describe the preparation,optimization,and application of NPs in photovoltaic semiconductors in this review.

Effect of vacuum heat treatment on microstructure and corrosion behavior of HVOF sprayed AICoCrFeNiCu high entropy alloy

To improve the corrosion resistance of coalbed methane drilling equipment,an AICoCrFeNiCu high entropy alloy coating was prepared on the AISI 4135(35CrMo)steel substrate by high velocity oxygen fuel(HVOF)technology,and the coating was subjected to vacuum heat treatment(VHT)at different temperatures(500,700,900 and 1100℃).The corrosion test of the substrate and the coatings after VHT in coalbed methane drilling fluid was carried out.The results show that the HVOF sprayed AICoCrFeNiCu high entropy alloy(HEA)coating has a good bonding with the substrate,and the porosity of the coating is about 2.4%.There is partial segregation in the coating,and the coating mainly consists of body-centered cubic phase.The coating has good thermal stability,and the phase structure and microstructure of the coatings have changed after VHT at different temperatures.Compared with the substrate,the as-sprayed coating has better uniform corrosion resistance,and the corrosion resistance of the coating after VHT is further improved.After VHT at 500℃,the HVOF-sprayed AICoCrFeNiCu HEA coating has the best corrosion resistance.

Effect of temperature and mating pair on tribological properties of DLC and GLC coatings under high pressure lubricated by MoDTC and ZDDP

Diamond-like carbon(DLC)and graphite-like carbon(GLC)coatings have good prospects for improving the surface properties of engine parts.However,further understanding is needed on the effect of working conditions on tribological behaviors.In this study,GLC and two types of DLC coatings were deposited on GCr15 substrate for investigation.The friction and wear properties of self-mated and steel-mated pairs were evaluated.Two temperatures(25 and 90℃),three lubrication conditions(base oil,molybdenum dithiocarbamate(MoDTC)-containing oil,MoDTC+zinc dialkyldithiophosphate(ZDDP)-containing oil),and high Hertz contact stress(2.41 GPa)were applied in the experiments.The results showed that high temperature promoted the effect of ZDDP on steel-mated pairs,but increased wear under base oil lubrication.The increased wear for steel-mated pairs lubricated by MoDTC-containing oil was due to abrasive wear probably caused by MoO_(3) andβ-FeMoO_(4).It was also found that in most cases,the tribological properties of self-mated pairs were better than those of steel-mated pairs.