  Phosphorus-doped diamond is relevant for applications in sensing,
optoelectronics and quantum photonics, since the unique optical properties of
color centers in diamond can be combined with the n-type conductivity attained
by the inclusion of phosphorus. Here, we investigate the photoluminescence
signal of the nitrogen-vacancy and silicon-vacancy color centers in
phosphorus-doped diamond as a function of temperature starting from ambient
conditions up to about 100$^\circ$ Celsius, focusing on the zero-phonon line
(ZPL). We find that the wavelength and width of the ZPL of the two color
centers exhibit a comparable dependence on temperature, despite the strong
difference in the photoluminescence spectra. Moreover, the temperature
sensitivity of the ZPL of the silicon-vacancy center is not significantly
affected by phosphorus-doping, as we infer by comparison with silicon-vacancy
centers in electronic-grade single-crystal diamond.
