@article{oai:kyutech.repo.nii.ac.jp:00000166,
 author = {Satake, Akihiro and 佐竹, 昭泰 and Shiraishi, N and Takata, N and Fujiwara, Kenzo and 藤原, 賢三 and Schrottke, L and Grahn, H.T.},
 issue = {2-4},
 journal = {Physica E: Low-dimensional Systems and Nanostructures},
 month = {Mar},
 note = {We have studied the photoluminescence (PL) properties of a GaAs/AlxGa1−xAs quantum well (QW) systemconsisting of three QW’s with different thicknesses, in which the widest one (7.8 nm) has an excited-subband excitonstate located slightly below the barrier band edge. Using above-barrier excitation with a power density of about10 W/cm2 at 13 K, a strong PL emission peak appears on the high-energy side of the three PL peaks originating from theground-state exciton transitions of the three QW’s. This high-energy PL peak with an intensity comparable to the one ofthe other three peaks is located near an excited-subband (n=2) exciton state of the widest QW. By investigating theposition dependence of the PL spectra across a 2-inch wafer, which exhibits a decreasing Al mole fraction x from thecenter to the edge, the PL intensity of the high-energy peak can be correlated with the one of the ground-state in thewidest QW. This correlation indicates that this high-energy PL peak is most likely related to the n=2 exciton state of thewidest QW because of the energy alignment of the excited subband state relative to the barrier band edge.},
 pages = {641--645},
 title = {Strong Photoluminescence Emission from an Excited-Subband Exciton State in a GaAs/AlxGa1−xAs Triple Quantum Well with Different Well Thicknesses},
 volume = {21},
 year = {2004},
 yomi = {サタケ, アキヒロ and フジワラ, ケンゾウ}
}