Rate-Limited Electroless Gold Thin Film Growth: A Real-Time Study

Abstract

Time-resolved, in situ spectroscopy of electroless (EL) gold (Au) films combined with electron microscopy showed that the deposition rate increased up to two-fold on surfaces swept by the bulk flow of adjacent fluid at Reynolds numbers less than 1.0, compared to batch immersion. Deposition rates from 5.0 to 9.0 nm/min and thicknesses of the EL Au film from 20 to 100 nm, respectively, increased predictably with flow rate at conditions when the deposition was limited primarily by Fickian diffusion. Time-frames were identified for metal island nucleation, growth, and subsequent film development during EL Au deposition by real-time UV-visible spectroscopy of photoluminescence (PL) and surface plasmon features of nanoscale metal deposits. Film thicknesses measured by scanning electron microscopy and X-ray photoelectron spectroscopy paired with real-time optical spectroscopy of kinetic aspects of plasmon and PL optical features indicated that Au film deposition on surfaces swept by a steady flow of adjacent fluid can be primarily diffusion limited.

Targeted Deposition of Platinum onto Gold Nanorods by Plasmonic Hot Electrons

“…More recently, the approach was extended to control size of copper (Cu) seeds reduced via laser prior to the catalytic Ge nanowire growth . Beyond plasmon-driven reactions, transmission UV–vis spectroscopy has improved analysis of mass transport in wet-chemical syntheses, e.g., morphological evolution of Au–Ag core–shell nanorods during anisotropic etching by ferric chloride and continuous-flow electroless Au film plating …”

“…10 Beyond plasmon-driven reactions, transmission UV−vis spectroscopy has improved analysis of mass transport in wet-chemical syntheses, e.g., morphological evolution of Au−Ag core−shell nanorods during anisotropic etching by ferric chloride 50 and continuous-flow electroless Au film plating. 51 Herein, transmission UV−vis spectroscopy was used to track UV absorbance of the L π MCT feature of PtCl 6 2− and NIR extinction of the AuNR LSPR. Although dark-field scattering spectroscopy used by Di Martino et al to monitor plasmonic photodeposition offers single-particle insights, it cannot be used monitor the precursor's state using LMCT absorption features in the UV range in parallel with LSPR of the plasmonic particle substrate.…”

Photothermal response of the plasmonic nanoconglomerates in films assembled by electroless plating

“…41 Au grain sizes between 30-40 nm for lms produced by electroless plating (ELP) have been reported in several studies. [39][40][41][42][43] In this work, batch electroless plating was used to prepare bare Au lm and Au lm decorated by ordered Au nanostructures. Fig.…”

Electron optics of nanoplasmonic metamaterials in bio/opto theranostics

“…42 Real-time spectroscopy of continuous flow electroless plating provides dynamic and equilibrium measures for metal deposition in successive electroless plating steps. 43 Tin chloride sensitization prior to lithography enhances meta-atom uniformity and sphericity 44 . Metal deposited into plasmonic thin films 45 and or near particle-46 or fibrous nanoarchitectures 47 can support in vitro analysis of macromolecular binding constants.…”