In-situ etching strategy to construct yolk-shell CoSe2@NiCoSe4@NC heterostructures for high-performance sodium ion battery

Yolk-shell structure CoSe2@NiCoSe4@NC has been successful synthesized through in-situ etching and ion exchange strategy, as well as the subsequent selenization process of the ZIF-67 dodecahedron precursor. Due to the unique...

Thermochemical synthesis of tribotechnical coatings based on molybdenum diselenide MoSe2 on structural steels

The study results of the influence of parameters of the process of chemical-thermal treatment in selenium vapor during the preparation of solid lubricating coatings from molybdenum diselenide on specimens of structural steels with a plasma Mo-coating are presented. An empirical mathematical model of the temperature-time parameters of the Mo selenization process is proposed, which makes possible to control the quality of the obtained coatings depending on requirements for their tribotechnical properties. An assessment of their tribotechnical characteristics in air and in vacuum in the temperature range 20—600 °С has been carried out.

An efficient Li+-doping strategy to optimize the band alignment of a Cu2ZnSn(S,Se)4/CdS interface by a Se&LiF co-selenization process

A novel and efficient co-selenization approach was proposed to promote the grain growth and optimize the band diagram.

CuZnSn(SxSe1-x)4 Solar Cell Prepared by the Sol-Gel Method Following a Modified Three-Step Selenization Process

In current work, Cu2ZnSn(S,Se)4 thin films have been prepared by the sol-gel method based on dimethyl sulfoxide solution followed by a modified three-step selenization process. The key process of this method is to divide the Se evaporation and annealing into two different stages: employ a thermal cracking Se source in the Se evaporation stage and an above-atmospheric pressure in the annealing process. The morphological, structural, elemental distributional, and photovoltaic properties of Cu2ZnSn(S,Se)4 thin films prepared with the three-step selenization process were systematically investigated. It was found that through this modified selenization process, the formations of secondary phases (ZnSe, CuSnSe3) and a fine-grain bottom layer, which usually exists in the traditional one-step selenization process, were effectively suppressed. These improvements could further reduce the carrier recombination and improve the solar cell performance. The best solar cell is obtained with a short-circuit current density of 28.16 mA/cm2, open-circuit voltage of 404.91 mV, fill factor of 62.91%, and a power conversion efficiency of 7.17% under air mass 1.5 (100 mW/cm2) illumination.