Anisotropic photoconductivity of InGaAs quantum dot chains measured by terahertz pulse spectroscopy

作者：Cooke DG^*; Hegmann FA; Mazur YI; Ma WQ; Wang X; Wang ZM; Salamo GJ; Xiao M; Mishima TD; Johnson MB

来源：Applied Physics Letters, 2004, 85(17): 3839-3841.

DOI：10.1063/1.1807959

We report results of time-resolved terahertz (THz) pulse spectroscopy experiments on laterally ordered chains of self-assembled InGaAs quantum dots photoexcited with 400 nm, 100 fs laser pulses. A large anisotropy in the transient photoconductive response is observed depending on the polarization of the THz probe pulse with respect to the orientation of the dot chains. Fast (3.5-5 ps) and efficient carrier capture into the dots and one-dimensional wetting layers underneath the dot chains is observed below 90 K. At higher temperatures, thermionic emission into the two-dimensional wetting layers and barriers becomes significant and the anisotropy in the photoconductive signal is reduced.

• 出版日期2004-10-25