One-step CZT electroplating from alkaline solution on flexible Mo foil for CZTS absorber

In this work, Cu-Zn-Sn (CZT) is co-electrodeposited onto a flexible Mo substrate exploiting an alkaline bath (pH 10). The plating solution is studied by cyclic voltammetry, highlighting the effects of potassium pyrophosphate (K4P2O7) and EDTA-Na2 on the electrochemical behavior and stability of the metallic ionic species. The optimized synthesis results in a homogeneous precursor layer, with composition Cu 44 ± 2 at. %, Zn 28 ± 1 at. %, and Sn 28 ± 2 at. %. Soft and reactive annealing are employed respectively to promote intermetallic phase formation and sulfurization of the precursor to obtain CZTS. Microstructural (XRD, Raman), morphological (SEM), and compositional (EDX, XRF) characterization is carried out on CZT and CZTS films, showing a minor presence of secondary phases. Finally, photo-assisted water splitting tests are performed considering a CZTS/CdS/Pt photoelectrode, showing a photocurrent density of 1.01 mA cm−2 at 0 V vs. RHE under 1 sun illumination. Graphical abstract

Pure Sn Coatings Produced by Pulse Plating from Stannate Bath

We have produced pure Sn coatings from an alkaline bath plating. The plating bath was composed of sodium stannate and sodium hydroxide with sorbitol as an additive. The experiments were performed with a potentiostat/galvanostat at various current densities from 5–25 mA/cm2. The morphology of the coatings, thickness, plating rate, and microhardness were evaluated. Furthermore the wetting of the Sn coatings on a Cu substrate was also assessed by area spread ratio measurements after reflow at 250 °C. The resultant coatings were very smooth and shiny. Initially, the plating morphology was uneven and a nodular type, which further improved with increasing current density up to 15 mA/cm2. The plating rate and thickness were the maximum at a current density of 15 mA/cm2. The coatings had higher strength and solderability at 15 mA/cm2 due to the improved microstructure and plating rate.

Effect of pH on the characteristics of electroless Ni-P coatings

In this study electroless Ni-P coatings were deposited on W302 steel substrates. The effects of bath pH and heat treatment at 400?C were investigated on the surface morphology, phase structure, phosphorus content, thickness and microhardness of the coatings. It was observed that both the phosphorus content and coating thickness are dependent on the bath pH. In an acidic/neutral bath, low and medium phosphorus coatings with thickness of 13.9-19.8 ?m were synthesized, while in an alkaline bath, high phosphorus, 4.8-5.8 ?m-thick coatings were formed. Coatings containing medium or high P seemed to be amorphous, while low P coatings had microcrystalline structures. Hardness was also dependent on the composition of the coating. After heat treatment, the structure of the coatings transformed into crystalline Ni with the precipitation of Ni3P phases, which resulted further increases in hardness.