Abstract-Temperature dependence of the point defect properties of GaN thin films studied by terahertz time-domain spectroscopy

• HeNan Fang, 
• Rong Zhang, 
• Bin Liu, 
• YeCao Li, 
• DeYi Fu, 
• Yi Li, 
• ZiLi Xie, 
• Zhe Zhuang, 
• YouDou Zheng,
• JingBo Wu, 
• BiaoBing Jin, 
• Jian Chen, 
• PeiHeng Wu, 

• http://link.springer.com/article/10.1007%2Fs11433-013-5202-6

The dielectric functions of GaN for the temperature and frequency ranges of 10–300 K and 0.3–1 THz are obtained using terahertz time-domain spectroscopy. It is found that there are oscillations of the dielectric functions at various temperatures. Physically, the oscillation behavior is attributed to the resonance states of the point defects in the material. Furthermore, the dielectric functions are well fitted by the combination of the simple Drude model together with the classical damped oscillator model. According to the values of the fitting parameters, the concentration and electron lifetime of the point defects for various temperatures are determined, and the temperature dependences of them are in accordance with the previously reported result. Therefore, terahertz time-domain spectroscopy can be considered as a promising technique for investigating the relevant characteristics of the point defects in semiconductor materials.