教師著作

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Browsing 教師著作 by Author "C.-B. Tsai"

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    Size Dependent Properties of CdSe Quantum Dots
    (American Physical Society, 2005-05-23) S. Neeleshwar; C.-L. Chen; C.-B. Tsai; Y.-Y. Chen; Chia-Chun Chen; S.-G. Shyu; M.-S. Seehra
    Temperature dependences of the magnetic susceptibility χ and heat capacity Cp of CdSe quantum dots with size d=2.8, 4.1, and 5.6 nm are compared to those of bulk CdSe to determine the size-dependent effects. With decreasing size d, the following effects are observed: (i) room temperature optical absorption shows a blueshift of the band gap; (ii) room temperature x-ray diffraction show wurtzite structure but with smaller lattice constants; (iii) magnetic susceptibility changes from negative (diamagnetic) for the bulk to positive χ with magnitude increasing with decreasing d; and (iv) the Sommerfeld constant γ determined from the Cp/T vs T2 data increases. Possible explanations for these size-dependent properties are presented.