Ion‐implanted crystalline silicon annealed in atomic hydrogen photoluminesces at 0.99±0.01 eV in a band having a spectral width of 0.1 eV FWHM. The emitted spectrum does not depend on the chemical nature of the implanted ion (Al, As, D, F, H, Ne, P, Si); however, when the surface is amorphized, a spectrum characteristic of hydrogenated amorphous Si is obtained.