標題: | Photogeneration of coherent shear phonons in orientated wurtzite semiconductors by piezoelectric coupling |
作者: | Wen, Yu-Chieh Ko, Tsung-Shine Lu, Tien-Chang Kuo, Hao-Chung Chyi, Jen-Inn Sun, Chi-Kuang 光電工程學系 光電工程研究所 Department of Photonics Institute of EO Enginerring |
關鍵字: | gallium compounds;III-V semiconductors;phonons;piezoelectric semiconductors;ultrasonic effects;wide band gap semiconductors |
公開日期: | 1-十一月-2009 |
摘要: | Using piezoelectric wurtzite semiconductor with accurate control of the crystal cut, we investigate the photogeneration of coherent shear acoustic phonons through anisotropic piezoelectric coupling. Theoretical study suggests the dominant contribution of the piezoelectric effect to the shear phonon generation in a-plane wurtzite GaN, which is also confirmed by the picosecond ultrasonic experiments with different dopant and excitation conditions. Piezoelectric transduction thus explains the observed remarkable coherent shear phonon signal. The influence of the ultrafast screening of surface electric field by photocarriers on the intensity and waveform of the generated shear acoustic pulse are discussed. |
URI: | http://dx.doi.org/10.1103/PhysRevB.80.195201 http://hdl.handle.net/11536/6458 |
ISSN: | 2469-9950 |
DOI: | 10.1103/PhysRevB.80.195201 |
期刊: | PHYSICAL REVIEW B |
Volume: | 80 |
Issue: | 19 |
起始頁: | 0 |
結束頁: | 0 |
顯示於類別: | 期刊論文 |