Effect of annealing on the optical and electrical properties of dilute nitride GaAsSbN

• Main Authors: Wang-Shang Ping, 王尚平
• Other Authors: Hao-Hsiung Lin
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/03328153673638321292

碩士 === 國立臺灣大學 === 電機工程學研究所 === 97 === This study is about the changes of electronic and optical properties that occur when the dilute nitride GaAsSbN is annealed. In our work, the effect of annealing temperature and duration on the bulk material was systematically investigated, trying to find an optimal annealing condition. Though the thermal treatment annihilates non-radiative centers, restores as-grown defects and enhances photoluminescence (PL) intensities, it induces acceptor-type defects and increases the hole concentrations in the samples, leading to the conduction-type conversion in un-doped GaAsSbN. The formation energy of the defect, determined from Arrhenius plot, is within 2.7~3.8 eV, revealing that the defects could be Ga vacancies. The improvement in PL intensity accompanies with the blue-shift in emission energy. And the origins of this annealing-induced blue-shift in PL peak energy include the homogenization of nitrogen atoms, the reduction in tail states, and the filling effect due to the increment in carrier density. We also compared MBE annealed samples with RTA annealed and the result shows that MBE annealed set can achieve higher PL intensity and better photo responsivity. Finally, we found that annealing at 600°C with longer duration can achieve higher PL intensity and less blue shift than at higher temperatures with shorter duration. At last, we have successfully fabricated GaAsSbN detectors with a cut-off wavelength >1.6 μm.