论文标题
异质结构中原子级界面扩大引起的局部能量状态
Localized Energy States Induced by Atomic-Level Interfacial Broadening in Heterostructures
论文作者
论文摘要
一个融合原子水平界面细节的理论框架被得出，包括埋入界面的电子结构，并描述有限界面宽扩大的异质结构中电荷载体的行为。将此模型应用于超薄杂型（SIGE）M/（SI）M超晶格，可预测由亚纳米宽片引起的带结构中的局部能级，这为孔 - 电子重组提供了其他途径。这些预测的界面电子过渡和相关的吸收作用在可变的超晶格厚度和周期性下实验证实。通过映射临界点的能量，可以在2至2.5 eV之间识别光学转变，从而将光吸收扩展到较低的能量。这种现象使异质结构中原子水平扩展的直接和无损探针具有直接和无损的探针。
A theoretical framework incorporating atomic-level interfacial details is derived to include the electronic structure of buried interfaces and describe the behavior of charge carriers in heterostructures in the presence of finite interfacial broadening. Applying this model to ultrathin heteroepitaxial (SiGe)m/(Si)m superlattices predicts the existence of localized energy levels in the band structure induced by sub-nanometer broadening, which provides additional paths for hole-electron recombination. These predicted interfacial electronic transitions and the associated absorptive effects are confirmed experimentally at variable superlattice thickness and periodicity. By mapping the energy of the critical points, the optical transitions are identified between 2 and 2.5 eV thus extending the optical absorption to lower energies. This phenomenon enables a straightforward and non-destructive probe of the atomic-level broadening in heterostructures.
