@article{oai:kyutech.repo.nii.ac.jp:00001143,
 author = {Fujiwara, Kenzo and 藤原, 賢三 and Tsukada, N and Nakayama, T and Nakamura, A},
 issue = {2},
 journal = {Physical review B. Condensed matter},
 month = {Jul},
 note = {Perpendicular transport of photoexcited carriers, which sink into an intentionally enlarged quantum well, is investigated in a set of GaAs/AlAs short-period superlattices with systematically varied AlAs barrier thicknesses as a function of the lattice temperature between 4.2 and 200 K. Excitation-power dependence of the luminescence observed at low temperatures indicates that the ambipolar transport is operative at carrier densities in excess of 1015–1017 cm−3. We find that tunneling-assisted hopping conduction prevails at low temperatures via localized states and that the tunneling probability is correlated with the calculated heavy-hole miniband width. We also find a crossover from the hopping conduction to the Bloch-type transport at higher temperatures, which critically depends on the barrier thickness, as a result of thermal activation of carriers to the extended miniband states.},
 pages = {1096--1101},
 title = {Perpendicular transport of photoexcited electrons and holes in GaAs/AlAs short-period superlattices: Barrier-thickness and temperature dependence},
 volume = {40},
 year = {1989},
 yomi = {フジワラ, ケンゾウ}
}