Pump-probe measurement of lifetime engineering in SiGe quantum wells below the optical phonon energy

Pidgeon, C.R., Phillips, P.J., Carder, D., Murdin, B.N., Fromherz, T., Paul, D.J. , Ni, W.X. and Zhao, M. (2005) Pump-probe measurement of lifetime engineering in SiGe quantum wells below the optical phonon energy. Semiconductor Science and Technology, 20(10), L50-L52. (doi: 10.1088/0268-1242/20/10/l02)

Abstract

We have directly determined with pump/probe spectroscopy the light hole (LH1) excited state lifetime for the lowest heavy hole to light hole intrawell subband transition (HH1–LH1) for three prototype samples of Si/SiGe strain-symmetrized multi-quantum well structures, designed to have the final LH1 state increasingly unconfined. The transition energy is below the optical phonon energy. We find that a decay time of 20 ps for sample 1 with a well width of 5.0 nm lengthens to 40 ps for sample 3 with a well width of 3.0 nm, in good agreement with the design. In addition, we have measured the lifetime for holes excited out of the well, from which we determine the lifetime for diagonal transitions (back into the well) to be of approx. several hundred picoseconds.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Paul, Professor Douglas
• Authors: Pidgeon, C.R., Phillips, P.J., Carder, D., Murdin, B.N., Fromherz, T., Paul, D.J., Ni, W.X., and Zhao, M.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Research Group: Semiconductor Devices
• Journal Name: Semiconductor Science and Technology
• Publisher: IOP Publishing
• ISSN: 0268-1242
• ISSN (Online): 1361-6641