LP2N, Université de Bordeaux , F-33405 Talence, France.
ACS Nano. 2014 Nov 25;8(11):11651-6. doi: 10.1021/nn5049409. Epub 2014 Oct 27.
We use nominally spheroidal CdSe nanocrystals with a zinc blende crystal structure to study how shape perturbations lift the energy degeneracies of the band-edge exciton. Nanocrystals with a low degree of symmetry exhibit splitting of both upper and lower bright state degeneracies due to valence band mixing combined with the isotropic exchange interaction, allowing active control of the level splitting with a magnetic field. Asymmetry-induced splitting of the bright states is used to reveal the entire 8-state band-edge fine structure, enabling complete comparison with band-edge exciton models.
我们使用具有闪锌矿晶体结构的近球形 CdSe 纳米晶体来研究形状微扰如何消除能带边激子的能量简并。低对称度的纳米晶体由于价带混合和各向同性交换相互作用，导致上、下亮态简并都发生劈裂，从而可以通过磁场对能级劈裂进行主动控制。亮态的不对称劈裂用于揭示整个 8 态能带边精细结构，从而可以与能带边激子模型进行完全比较。
