设计了(CdZnTe,ZnSeTe)/ZnTe复合量子阱结构,并用吸收光谱、室温光致发光谱和飞秒脉冲抽运-探测方法研究了该复合结构中的激子隧穿过程.分别测量了该结构中CdZnTe/ZnTe量子阱层和ZnSeTe/ZnTe量子阱层中激子衰减时间.观察到从CdZnTe/ZnTe量子阱层向ZnSeTe/ZnTe量子阱层的快速激子隧穿,隧穿时间为5.5 ps.
The geometrical structure of semiconductor clusters including Zn3O3 was optimized by the DFT B3LYP method. With the same basis sets, dipole moments, polarizabilities and secondorder hyperpolarizabilities have been calculated and compared with the results obtained by TDDFT B3LYP method combined with sum-over-state （SOS） formula. The calculation results indicate that the dipole moments of the ground state depend on the atom radius and electronegative differences between elements and are their balance point as well. The polarizabilities of the clusters accord with the rule of the corresponding energy transformation from ground to excited state. The results predict an increase of second-order hyperpolarizabilities with increasing the distances between atoms in the clusters as well as a decrease of the polarizabilities and second-order hyperpolarizabilities in the same serial of semiconductor clusters with increasing the dipole moments of the ground states. The changes of dipole moments in ground states are inconsistent with transition moments. Spatial structure, charge transfer and other factors play an important role in composing the transition moments.
