The temperature dependence of the terahertz (THz) radiation from semi-insulating InP surfaces excited by ultrashort laser pulses has been studied in detail between 10 and 300 K. It is found that the electric field of the radiated THz waves show opposite polarity at low and high temperatures for low-density excitation. The temperature dependence is explained by the competing model of the drift and the diffusion currents. Good agreement between the experimental results and the calculations based on the drift-diffusion model shows that the dominant radiation mechanism is the current surge effect due to the surface electric field at high temperatures and the photo-Dember effect at low temperatures.
|ジャーナル||Physical Review B - Condensed Matter and Materials Physics|
|出版ステータス||Published - 2003 5 7|
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