Solvothermal growth of Zn_(2)SnO_(4) for efficient dye-sensitized solar cells

Zn_(2)SnO_(4)plates,particles and spheres are suc-cessfully prepared via a facile synthesis way by carefully adjusting the solvothermal conditions,which are further applied as photoanodes in dye-sensitized solar cells(DSSCs)to explore the relationships between the pho-toanode nanostructure and the photovoltaic performances.As a result,the DSSCs based on Zn_(2)SnO_(4)spheres pho-toanode showcased the best power conversion efficiency(PCE,4.85%),compared to Zn_(2)SnO_(4)plates(3.80%)and particles(4.13%).It is found that Zn_(2)SnO_(4)spheres exhibit the highest light-scattering abilities,as evidenced by ultraviolet–visible(UV–Vis)diffuse reflectance spectra.Additionally,investigations on dynamic electron transport and recombination properties via intensity-modulated photovoltage/photocurrent spectroscopy(IMVS/IMPS),and electrochemical impedance spectroscopy(EIS)mea-surements demonstrate that the Zn_(2)SnO_(4)spheres-based DSSCs possess the fastest electron transport rate,the longest electron lifetime,the highest electron collection efficiency(ηc c),and the largest charge recombination resistance,compared with the Zn_(2)SnO_(4)plates and particles,all of which are highly beneficial for the powder conversion efficiency enhancements.

Additive manufacturing of Cu-AI-Mn shape memory alloy with enhanced superelasticity

The Cu-based shape memory alloy(SMA)with highly oriented columnar crystals is an ideal candidate for the commercial application,especially the ones obtained through rapid cooling via additive manufacturing method.In this work,Cu_(71)Al_(18)Mn_(11)(at%)shape memory alloy with strong<001>texture columnar grains was successfully prepared by selective laser melting(SLM).An L27(313)orthogonal array was designed to systematically investigate the effects of laser power,scanning speed,scanning spacing,layer thickness and their interactions on the forming quality of Cu_(71)Al_(18)Mn_(11)alloys.Cu_(71)Al_(18)Mn_(11)alloys with density of 7.3204 g·cm^(-3)and relative density of 99.18%were successfully prepared when the laser power,scanning speed,scanning distance and layer thickness were 240 W,1000 mm·s^(-1),0.11 mm and 25μm,the transformation onset temperature(Ms),martensite phase transformation termination temperature(Mf),austenite phase transformation onset temperature(AS)and austenite phase transformation termination temperature(Af)are-21.84,-26.04,-15.75 and-12.36℃,respectively.The compression strength and fracture strain along the building direction(BD)were significantly superior to the scanning direction(SD),while the superelasticity of compression along the SD reached 2.50%,which was better than that of2.32%along BD.The mechanical property and superelasticity anisotropy due to the formation of columnar grains and texture were discussed.This study shows that SLM is a proposed method for the preparation of Cu-Al-Mn SMAs with high superelasticity,which provides a new strategy for enhancing the shape memory alloy superelasticity.