Visible-light irradiation has been employed to promote a chemical reaction of 1-hexadecene with hydrogen-terminated silicon, yielding alkyl chains directly immobilized on bulk silicon surface. The resulting monolayer, that is, one type of self-assembled monolayer, was examined with water contact angle measurements, x-ray photoelectron spectroscopy, atomic force microscopy, and ellipsometry. While a part of the silicon surface was oxidized during the reaction, it was demonstrated that a compact monolayer was successfully formed both on p- and n-typed silicon substrates regardless of doping density. (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3065485]