Carrier Dynamics and Dynamic Band-Bending in Type-II ZnTe/ZnSe Quantum Dots
M. Sypereka, J. Misiewicza, C.H. Chanb, D.O. Dumcencob, Y.S. Huangb and W.C. Chouc
aInstitute of Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
bDepartment of Electronic Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan
cDepartment of Electrophysics, National Chiao Tung University, Hsin Chu 300, Taiwan
Full Text PDF
Carrier dynamics and dynamic band-bending in self-assembled ZnTe/ZnSe quantum dots have been studied by means of time-resolved photoluminescence experiment at low temperatures. The experiment reveals clearly type-II character of the confinement potential in the dot manifested in: (i) long photoluminescence decay time constant of 28-35 ns, and (ii) temporal shift of the quantum dot peak emission towards low energy following the laser pulse excitation. The magnitude of the spectral shift ΔE depends on the dot size and the power density of excitation pulse. For the dots under study and given experimental conditions ΔE ≈ 28 ÷ 42 meV.

DOI: 10.12693/APhysPolA.124.821
PACS numbers: 78.67.Hc, 78.55.Et, 78.47.J-