ε-GaSe crystals are grown with the stoichiometric GaSe of 0.05%, 0.1%, 0.5%, 1% and 2%(mass percent) Te and are characterized by GaSe:Te(0.01%, 0.07%, 0.38%, 0.67% and 2.07%(mass percent)) crystals. The transformation of the rigid layer phonon modes with doping is studied for the first time. The absorption peak of the rigid mode E'(2) centered at ~0.59 THz is rising up in the intensity till reaching a maximal value on the first stage of the doping concentration less than 0.38%(mass percent). This process correlates well with the improvement in the optical property. Further doping is resulting in the decrease of the intensity till vanishing the E'(2) absorption peak at 1%(mass percent) Te. Simultaneously with the E'(2) absorption peak decreasing, the absorption peak of the rigid mode E'(2) centered at 1.78 THz is rising up in the intensity. The two processes correlate well with the degradation in the optical quality of GaSe:Te crystal. The doping level that results in the highest intensity of the absorption peak of the rigid layer mode E'(2) is proposed as a criterion in the identification of the optimal Te-doping in GaSe crystal that is confirmed by THz generation via optical rectification.
|Number of pages||7|
|State||Published - 1 Dec 2011|
- Crystal growth
- Optical property
- Te crystal