Phonon sidebands of intersubband absorption in AlGaN/GaN high-electron-mobility transistors

Wang, Z.; Reimann, K.; Woerner, M.; Elsaesser, T.; Hofstetter, Daniel; Hwang, Jeff; Schaff, William J.; Eastman, Lester F.

doi:10.1016/j.physe.2005.12.132

Phonon sidebands of intersubband absorption in AlGaN/GaN high-electron-mobility transistors

Author(s)

Wang, Z.

Reimann, K.

Woerner, M.

Elsaesser, T.

Hofstetter, Daniel

Laboratoire temps-fréquence

Hwang, Jeff

Schaff, William J.

Eastman, Lester F.

Date issued

2006

In

Physica E: Low-dimensional Systems and Nanostructures, Elsevier, 2006/32/1-2/562-565

Abstract

Femtosecond two-color pump-probe experiments in the mid-infrared are performed on intersubband transitions in a GaN/Al<sub>0.8</sub>Ga<sub>0.2</sub>N heterostructure. In these experiments, we observe around zero time delay distinct phonon sidebands, which disappear because of spectral diffusion with a time constant of 80 fs. The signal itself decays with a time constant of 380 fs. The independent boson model agrees very well with all observed results.