YANG-FANG CHEND. Y. LinY. S. HuangM. C. ChenHAO-HSIUNG LINJEN-CHEN FAN2018-09-102018-09-101999http://www.scopus.com/inward/record.url?eid=2-s2.0-0032621308&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/346820The quasibound states at the above barrier region in AlGaAs-GaAs superlattices can be clearly observed at room temperature by photoconductivity as well as photoreflectance measurements. Concrete evidence are provided to confirm that free carrier confinement at barrier layer does exist. The barrier width dependence of the above barrier transition energies can be described quite well by the modified Messiah's calculation. The simple calculation using the constructive interference condition can only explain the transitions at lower energies, and fails with increasing transition energy.Electron energy levels; Light reflection; Photoconductivity; Semiconducting aluminum compounds; Semiconducting gallium arsenide; Free carrier confinement; Photoreflectance measurement; Transition energy; Semiconductor superlatticesjournal article10.1063/1.3709652-s2.0-0032621308