Excitonics, an alternative to romising for processing information since semiconductor electronics is rapidly approaching the end of Moore’s law. Currently, the development of excitonic devices, where exciton flow is controlled, is mainly focused on electric-field modulation or exciton polaritons in high-Q cavities. Here, we show an all-optical strategy to manipulate the exciton flow in a binary colloidal quantum well complex through mediation of the Förster resonance energy transfer (FRET) by stimulated emission. In the spontaneous emission regime, FRET naturally occurs between a donor and an acceptor. In contrast, upon stronger excitation, the ultrafast consumption of excitons by stimulated emission effectively engineers the excitonic flow from the donors to the acceptors. Specifically, the acceptors’ stimulated emission significantly accelerates the exciton flow, while the donors’ stimulated emission almost stops this process. On this basis, a FRET-coupled rate equation model is derived to understand the controllable exciton flow using the density of the excited donors and the unexcited acceptors. The results will provide an effective all-optical route for realizing excitonic devices under room temperature operation.

由于半导体电子器件正迅速接近摩尔定律的末尾，因此Excitonics是取代信息处理的一种替代方法。当前，控制激子流的激子器件的开发主要集中在高Q腔中的电场调制或激子极化子上。在这里，我们展示了一种全光学策略，通过受激发射介导的Förster共振能量转移（FRET）来控制二元胶体量子阱复合物中的激子流。在自发发射方式中，FRET自然发生在供体和受体之间。相反，在更强的激发下，受激发射极快地消耗激子，从而有效地设计了从供体到受体的激子流。特别，受体的受激发射显着加速了激子流，而供体的受激发射几乎停止了该过程。在此基础上，推导了FRET耦合速率方程模型，以利用激发供体和未激发受体的密度来理解可控激子流。结果将为在室温操作下实现激子器件提供有效的全光途径。