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Electrochemical stabilization of crystalline silicon with aromatic self‐assembled monolayers in aqueous electrolytes
Author(s) -
Tutus Murat,
Purrucker Oliver,
Adlkofer Klaus,
Eickhoff Martin,
Tanaka Motomu
Publication year - 2005
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200541263
Subject(s) - monolayer , x ray photoelectron spectroscopy , contact angle , aqueous solution , dielectric spectroscopy , materials science , chemical engineering , electrochemistry , electrolyte , chemical stability , cyclic voltammetry , grafting , polymer , chemistry , nanotechnology , organic chemistry , electrode , engineering , composite material
We report stable chemical engineering of hydrogen‐terminated Si[111] surfaces in aqueous electrolytes by electrochemical grafting of aromatic monolayers. The topography and free energy of the engineered surface obtained from AFM and contact angle measurements confirmed homogeneous coating of the surface with a monolayer. Grafting of monolayers actually resulted in a clear suppression of the surface defect densities, demonstrated by photoluminescence lifetime. Changes in the surface chemical identities after grafting and post‐treatments were followed by X‐ray photoelectron spectroscopy (XPS). The electrochemical stability in aqueous electrolytes was assessed by impedance spectroscopy, revealing an improved stabilization of the Si/electrolyte interface by the grafted monomolecular film. This protocol was further applied for another aromatic compound, where the impact of 4‐substituent functions could clearly be detected by photovoltage measurements. The chemical and electrochemical stability achieved here is promising for the successive deposition of biocompatible polymer films and lipid membranes. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)