Excitation and deexcitation of Er3+ in crystalline silicon
Temperature dependent measurements of the 1.54 µm photoluminescence of Er implanted N codoped crystalline Si are made. Upon increasing the temperature from 12 to 150 K, the intensity quenches by more than a factor thousand, while the lifetime quenches from 420 to 3 µs. The quenching processes are described by an impurity Auger energy transfer model that includes bound exciton dissociation and a nonradiative energy backtransfer process. Electron and hole trap levels are determined. Direct evidence for a backtransfer process follows from spectral response measurements on an Er-implanted Si solar cell.