Oxygen (O)-terminated nanocrystalline silicon (nc-Si) films were prepared using silicon evaporation in an ultra-high vacuum with oxygen and argon radicals, and hydrogen (H)-termination of the nc-Si by HF solution treatment was tried in this work. The films were characterized by infrared (IR) absorption measurements in order to investigate the surface state of nc-Si in the films, which revealed that all of the Si-O bonds in the nc-Si films were replaced with Si-H bonds by HF solution treatment. The annealed samples exhibited strong photoluminescence (PL) with two peaks at ∼1.65 eV (∼750 nm) and ∼2.2 eV (∼560 nm), while no PL was observed from the H-terminated nc-Si. It was found that two PL signals are associated with Si-O related luminescence. [DOI: 10.1380/ejssnt.2005.527]