Photoluminescence Study of GaSe Doped with Er

The Er-doped GaSe crystal has been investigated by using temperature dependent photoluminescence (TDPL), a Fourier-transform infrared spectrometer (FTIR), and Hall effect measurements. The Er-doped GaSe appears to be a p-type semiconductor. The impurity level at ~2.064 eV is observed and located at ~64 meV above the valence band in both the as-grown and the annealed Er doped GaSe crystal. Additionally, the infrared luminescence and transmission spectra which have arisen from the intracenter transitions 4I9/2 → 4I15/2, 4I11/2 → 4I15/2, and 4I13/2 → 4I15/2 of erbium ions have been observed at ~0.81, 0.99, and 1.54 µm, respectively. The annealing process under excess Se atmosphere at 600°C for 72 h can enhance the crystal to have more active erbium ions.