Increasing energy conversion efficiency without any extra cost is required for crystalline silicon (c-Si) solar cells. Laser doping (LD) can meet these requirements because it can be performed in an ambient atmosphere at room temperature. In this study, spin-coated phosphorus silicate glass (PSG) was formed on textured c-Si as a precursor for LD. We found that after LD, the reinforcement of the interface between PSG and the Si surface improved the photovoltaic characteristics Voc and Jsc. The interface was reinforced by changing the c-Si surface from hydrophobic to hydrophilic before spin coating. The reinforced interface led to a reduction in the number of surface voids and an enhancement of the transfer of dopant atoms.