Eu 3+ -doped yttrium borate samples were prepared via a hydrothermal method using borate or tributyl borate as B 3+ sources, with and without carbon nanotubes as templates. The morphology of the samples is easily altered by varying the carbon nanotube template, B 3+ source and post-annealing treatment. Photoluminescence measurements indicate that the color purity of samples is clearly improved by template-assisted synthesis. Furthermore, with tributyl borate as the B 3+ source, CIE coordinates of (0.67,0.33), very similar to the (0.665,0.334) coordinates for the commercial red phosphor Y 2 O 2 S:Eu 3+ , can be obtained. Finally, an extra Eu 3+ −O 2− excitation band is observed for samples made by template-assisted synthesis. The underlying mechanism is discussed in detail.