Vertical resonant-cavity light emitting diodes with dual active regions consisting of highly n-doped Ge/GeSi multiple quantum wells (MQWs) and a Ge epilayer are proposed to improve the light emitting efficiency. The MQWs are designed to optically pump the underlying Ge epilayer under electric injection. Abundant excess carriers can be optically pumped into the Γ valley of the Ge epilayer apart from electric pumping. With the combination of a vertical cavity, the efficiency of the optical-pumping process was effectively improved due to the elongation of the optical length in the cavity. With the unique feature, optical gain from the Ge epilayer is observed between 1625 and 1700 nm at injection current densities of >1.528 kA/cm2. The demonstration of optical gain from the Ge epilayer indicates that this strategy can be generally useful for Si-based light sources with indirect band materials.

中文翻译：

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具有双有源区的垂直 Ge-on-Si 谐振腔发光二极管的光学增益

提出了具有由高度 n 掺杂的 Ge/GeSi 多量子阱 (MQW) 和 Ge 外延层组成的双有源区的垂直谐振腔发光二极管，以提高发光效率。MQW 设计用于在电注入下光泵浦底层 Ge 外延层。除了电泵浦外，还可以将大量多余的载流子光泵入 Ge 外延层的 Γ 谷。结合垂直腔体，由于腔体中的光程被拉长，有效提高了光泵浦过程的效率。凭借独特的功能，在注入电流密度 > 1.528 kA/cm2 时观察到 Ge 外延层的光学增益在 1625 到 1700 nm 之间。