A photoconductivity study of the excitons in doped and undoped GaAsAlGaAs quantum wells

✍ Scribed by P.O. Holtz; M. Sundaram; J.L. Merz; A.C. Gossard

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 259 KB
• Volume: 7
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1016/0749-6036(90)90115-n

✦ Synopsis

Photoconductivity (PC) measurements have been performed on narrow GaAs/A1GaAs quantum wells (QWs) using dye-laser excitation in a limited energy range: the vicinity of the excitons. The derived high resolution PC spectra are then compared with photoluminescence excitation (PLE) spectra in the same energy range for the same samples. In these PC spectra several new features appear, which to the best of our knowledge have not been reported earlier: In an undoped QW the excited 2s states in addition to the normally observed ls ground states to each of the heavy hole-(hh) and the light hole-(lh) states of the FE can be observed. Similarly, in a doped QW a peak interpreted as the bound exciton is observed on the low energy side of the FE. The same peaks can be observed also in PLE for the samples investigated, which is a strong support for the interpretation of the observed peaks. accordingly deteriorating. We have, on the contrary, in this PC study on narrow GaAs/AlxGal.xAs quantum wells (QWs), used dye-laser excitation in a limited energy range: