Erbium (Er) and nitrogen ions are coimplanted into Czochralski-grown s
ilicon. The excitation power dependence of the lifetime and the PL int
ensity of Er3+ ions shows that lifetime and the integrated PL intensit
y of Er3+ ions are decreased by a nonradiative energy back transfer fr
om optically activated Er. It is considered that the nonradiative ener
gy back transfer is caused by the temperature rise of the sample and t
he Auger process of excess carriers.