LAUSR

A recent study demonstrated adsorption of water molecules on the surfaces of carbon nanotubes (CNTs). Importantly, it was reported that the peak positions in the absorption and photoluminescence spectra of the CNTs were shifted to lower energy as the number of adsorbed water molecules increased. Here, we investigated the mechanism by which this redshift occurs by calculating the dielectric functions of CNTs following water adsorption using density functional theory. Our calculations reproduced the redshifts and demonstrated that they can be attributed to decreases in the band gaps, which result from electronic coupling between the CNTs and the water molecules.