Fundamental Aspects of Electrodeposition for the Realization of Plasmonic Nanostructures

Abstract

Electrodeposition is used for the preparation of nanoparticles and nanostructures that allow, in principle, surface plasmon excitation. The (photo)electrodeposition process of Rh and Au nanoparticles as well as of heterodimeric enzymes onto silicon surfaces is investigated and the resulting structures are discussed with regard to applications in photoelectroctalysis and biosensing. Electrodeposition of Rh onto H-terminated p-Si surfaces generates nanostructures of the metal nanoparticles with simultaneous oxidation of the substrate thus forming nano-dimensioned metal-oxide-semiconductor (MOS)-type contacts. The excess minority carrier harvesting in these nanoemitter structures, where semispherical space charge layers underneath the metal exist are discussed based on spectral sensitivity and capacitance measurements The deposition of Au nanoparticles by a combined chemical-electrochemical method on Si is presented as an example for sensing actuators where the resonance frequency is changed by adsorption. Similarly, site-selective deposition of the enzyme reverse transcriptase onto nanostructured (step-bunched) silicon serves as precursor experiment for biosensing in a Kretschmann-type ATR configuration. Future applications based on plasmonically active structures are outlined.

Raman Imaging in Biochemical and Biomedical Applications. Diagnosis and Treatment of Breast Cancer

“…There are many papers demonstrating that breast cancer oncology may benefit from SERS-active nanoparticles. They have been used in assays for prostate-specific antigen (PSA), BRCA1, and HER2, along with examples of nucleic acid detection. − …”

Operational principles of electrochemical nanoemitter solar cells for photovoltaic and photoelectrocatalytic applications

“…This drop is distributed according to the thickness and static dielectric constants of the structure according to Fig. 5b [38]. It would lower the band bending to about 0.6 eV.…”

Electronic and morphological properties of the electrochemically prepared step bunched silicon (111) surface

“…Results using synchrotron radiation photoelectron spectroscopy (SRPES) have shown that the surface of step bunched n‐type Si appears to be in an accumulation condition where the Fermi level at the surface is closer to the conduction band minimum than expected from the doping level 16. For future applications as bio‐sensors, in photoelectrocatalysis and in plasmonic sensing 19 it is of considerable interest to analyze the surface electronic properties, also with regard to their spatial behavior and to correlate them with the surface nanotopography.…”