论文标题
半导体纳米板片中的单电子和双电子自旋拉曼散射的理论
Theory of single and double electron spin-flip Raman scattering in semiconductor nanoplatelets
论文作者
论文摘要
提出了一种电子自旋叉拉曼散射（SFR）的理论，该理论描述了拉曼光谱信号在半导体纳米纤维素中的重孔激发量几乎共振的激发下被单个和两倍的电子Zeeman能量移动。我们分析了光激发的中间状态的自旋结构，得出了自旋裂纹散射的化合物基质元件，并获得了所有中间状态常见的单电子和两电子SFR的极化特性。我们表明，在所考虑的共振散射过程中，复合物“激子和局部居民电子”起着主要中间状态而不是紧密结合的TRION状态的作用。证明，除了直接的光激发（和类似的光聚合）通道外，还有另一个间接通道有助于SFRS过程。在间接通道中，光孔形成激子状态，而光电子局部位于本网站上的同时，从定位部位删除了居民电子。将理论结果与CDSE纳米片的集合的最新实验结果进行了比较。
A theory of electron spin-flip Raman scattering (SFRS) is presented that describes the Raman spectral signals shifted by both single and twice the electron Zeeman energy under nearly resonant excitation of the heavy hole excitons in semiconductor nanoplatelets. We analyze the spin structure of photoexcited intermediate states, derive compound matrix elements of the spin-flip scattering and obtain polarization properties of the one- and two-electron SFRS common for all the intermediate states. We show that, in the resonant scattering process under consideration, the complexes "exciton plus localized resident electrons" play the role of main intermediate states rather than tightly bound trion states. It is demonstrated that, in addition to the direct photoexcitation (and similar photorecombination) channel, there is another indirect channel contributing to the SFRS process. In the indirect channel, the photohole forms the exciton state with the resident electron removed from the localization site while the photoelectron becomes localized on this site. The theoretical results are compared with recent experimental findings for ensembles of CdSe nanoplatelets.
