Electrodeposition of White Bronzes on the Way to CZTS Absorber Films

Abstract

In order to substitute traditional cyanide-based baths and obtain a new eco-compatible route to synthesize via electrodeposition a CZTS (copper-zinc-tin sulfide) absorber films, this paper describes the development of a green electrodeposition bath for Cu–Sn alloys. CZTS, being a p-type semiconducting material could be used in novel and sustainable photovoltaic devices. In this work we analyzed the electrochemical behavior of different methanesulfonic acid-based prototype deposition bath containing tin methanesulfonate as tin precursor, copper sulfate or methanesulfonate as copper precursor, and hydroquinone, nitrilotriacetic acid and 2-picolinic acid as organic additives. Electrodeposition was conducted with different deposition parameters such as deposition potential, current density, potentiostatic or galvanostatic mode. Surface and cross-section morphology as well as composition of the films were characterized using SEM-EDS. The composition of the samples in terms of crystalline phases was analyzed using XRD, highlighting the information obtained by superlattice diffraction peaks based on the crystallography of Cu–Sn intermetallic phases. From prototype bath S4 a uniform composition around Cu:Sn = 2:1 was observed with η ′ phase as the dominant phase, which could possibly facilitate the synthesis of CZTS due to its aligned body-center vacancies that could serve as sulfur diffusion path during sulfurization within each η ′ crystal.

Optimisation of Thiourea Concentration in a Decorative Copper Plating Acid Bath Based on Methanesulfonic Electrolyte

“…The bath used in this work contained 4.62 M methanesulfonic acid (MSA) as the electrolyte, 0.17 M copper(II)-methanesulfonate as copper precursor, 0.1 M nitrilotriacetic acid (NTA) as copper ion complexing agent, 0.09 M hydroquinone (Hyd) as dissolving agent and thiourea (TU) as the organic additive under study in concentrations of 30, 60, and 90 ppm. Hydroquinone was used as a nitrilotriacetic acid (NTA) dissolving agent, as already reported in the literature [18], because the dissolution of NTA in the water/MSA system gave an unstable solution due to the fact of its poor solubility. Electrochemical measurements and depositions were carried out with a Metrohm (Herisau, Switzerland) Autolab mod.…”

In Situ Oxidizing Commercial Alloy to Achieve Selective Solar Absorption with High-Temperature Stability

“…However, they suffer complex devices and high cost, limiting their large-scale application. Some low-cost methods, such as anodization , and electrochemical deposition, , also suffer from the poor thermal stability of SSAs and are not environmentally friendly.…”

Chemical Stability of Pyrophosphate-Trilonate Electrolyte

“…Наявність або швидкість протікання реакції (1) залежить від співвідношення міцності комплексів металів в обох ступенях окиснення. У випадку утворення нерозчинних гідроксосполук Sn(IV), які можуть утворюватися протягом декількох діб [9], виникає необхідність постійного фільтрування електроліту. Накопичення у електроліті сполук Сu(I) призводить до погіршення якості покриттів через їх розряд на катоді в умовах граничного струму.…”

“…Для зниження впливу кисню повітря, до електроліту обмежують доступ повітря, в міжелектролізний період додають стабілізатори [15] -антиокстданти з окисно-відновним потенціалом, нижчим за рівноважним потенціалом кисню [9], наприклад, гідрохінон, який діє за реакціями:…”