The nonlinear and saturable absorption characteristics of Ga0.90In0.10Se and Ga0.85In0.15Se semiconductor crystals and their amorphous thin films

Date

2011-07-01

Author

KARATAY, AHMET
Aksoy, Cagla
YAĞLIOĞLU, HALİME GÜL
ELMALI, Ayhan
Kurum, Ulas
ATEŞ, AYTÜNÇ
Hasanlı, Nızamı

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

3
views

0
downloads

We investigated the nonlinear and saturable absorption characteristics of Ga0.90In0.10Se and Ga0.85In0.15Se semiconductor crystals and their very thin amorphous films by open aperture (OA) Z-scan and pump-probe techniques. The linear absorption spectra indicated a blue shift in energy with increasing film thickness. This can be attributed to the quantum confinement effect. For both 4 ns and 65 ps pulse durations the two photon absorption coefficients of Ga0.90In0.10Se and Ga0.85In0.15Se crystals increased with increasing input intensities. The life time of the localized defect states was measured as 3 ns for both Ga0.90In0.10Se and Ga0.85In0.15Se films while it was around 10 ns for GaSe and InSe films. Open aperture Z-scan experiments with a 4 ns pulse duration did not exhibit any saturable absorption behavior for thin films since the life time of localized defect states was not long enough to saturate these films. Thinner films exhibited saturable absorption and thicker films exhibited nonlinear absorption for a 65 ps pulse duration. This behavior was attributed to increasing localized defect states with increasing film thickness. The experimental curves were fitted to the theory of the open aperture Gaussian-beam Z-scan based on the Adomian decomposition method incorporating one photon, two photon, and free carrier absorptions and their saturations. The lowest saturation intensity threshold for the Ga0.90In0.10Se film was found to be 1.38 x 10(2) MW cm(-2) for 43 nm film thickness.

Subject Keywords

Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials

URI

https://hdl.handle.net/11511/41282

Collections

Department of Physics, Article