Terahertz emission mechanisms in InAsxP1-x.

The terahertz emission mechanisms from the surface of bulk InAsxP1-x crystals have been examined. The dominant terahertz emission mechanism from InAsxP1-x for low-fluence optical excitation is the photo-Dember effect for As compositions of 78% and greater while the surface field effect is dominant for As compositions of 50% and lower for the measured transport properties. The observed terahertz emission magnitude from the photo-Dember effect increased with As composition due to decreasing absorption depth. The observed terahertz emission magnitude from the surface field effect decreased with increasing As composition and was lower than modeled values due to the lower high-field mobility in the depletion region in those samples. [ABSTRACT FROM AUTHOR]