Open AccessCompetition between band filling effect and band-gap renormalization effect in GaAs
Author(s) -
Teng Li-Hua,
Xia Wang,
Tianshu Lai
Publication year - 2011
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.60.047201
Subject(s) - renormalization , saturation (graph theory) , band gap , absorption (acoustics) , materials science , condensed matter physics , relaxation (psychology) , absorption spectroscopy , physics , optics , quantum mechanics , psychology , social psychology , mathematics , combinatorics
Time-resolved linearly polarized pump-probe spectroscopy is used to investigate carrier relaxation dynamics in instrinsic GaAs. Absorption saturation and absorption enhancement are observed. It is found that the absorption saturation can be observed obviously when the photon energy is smaller than 1.549eV, otherwise, the absorption enhancement can be observed at a carrier density of 2×1017 cm-3. When the carrier density is above 7×1016 cm-3, the absorption enhancement increases rather than decreases with delay time. The simulation results with consideration of the competition between band filling effect and band-gap renormalization effect are in good agreement with our experimental results. With the band filling effect and band-gap renormalization effect considered, we develop a new analytical model to retrieve the carrier lifetime.