关键词: 太赫兹时域光谱, GaN薄膜, 光学性质

Abstract: At present, terahertz time-domain spectroscopy (THz-TDS) has become an effective tool to investigate the optical parameters and dispersion relationships of solids. The absorption spectra, dielectric constants, refractive indices and dielectric losses of GaN thin films with fibrillar zincite structure in the range of 0-8.0 THz are investigated using terahertz time-domain spectroscopy. The results show that the terahertz response with a frequency of 4.65 THz is dominated by the E₂(low) phonon mode of GaN, and the obtained low-frequency dielectric constant of 8.9 and high-frequency dielectric constant of 6.0 are close to the theoretical values. The terahertz dielectric constant response spectra with frequencies between 4.24 THz and 4.40 THz are further investigated. The obtained center vibration frequencies of the GaN films are consistent with the terahertz absorption spectra, and the value of the dielectric loss is very small and tends to be close to 0 gradually, indicating that GaN has good dielectric properties. The conclusions drawn expand the application of GaN-based electronic components in the THz band and are useful for further research on the quality and reliability of GaN-based electronic components in the THz band.

Key words: terahertz time-domain spectroscopy, GaN thin films, optical properties