The effect of naphthalene-based additives on tin electrodeposition on a gold electrode

In this work, we study the adsorption behavior of naphthalene derivatives: (NPT), naphthalenesulfonate (NPTS), hydroxynaphthalenesulfonate (HNPTS) and ethoxylated ?-napthalenesulfonic acid (ENSA, a commonly used additive in tin electroplating industry), on gold electrodes their effect electrodeposition process, by means situ ex surface analysis techniques (cyclic voltammetry, Surface Enhanced Raman Spectroscopy Scanning Electron Microscopy). From experiments density functional theory calculations, conclude formation films NPT, NPTS, HNPTS ENSA, where NPT NPTS lie flat ENSA undergo oxidative polymerization. The nature stability are strongly dependent structure, interaction between molecules, applied potential. is observed to form denser film than due attractive interactions adsorbed molecules tin. Tin affected presence films. bulk inhibited but slightly promoted HNPTS. deposits grown NTPS have same morphology, characteristic size electrodeposited features smaller absence. deposit exhibits markedly different features. Some amount sulfur incorporated as result reductive desulphonation electrode. was compared results obtained with similar during deposition process terms voltammetry deposition, it severely inhibits deposition. Naphthalene derivatives an show no or little AuSn (surface) alloys, which ascribed slow Sn UPD SnAu alloying process.