论文标题
直接可视化动量禁止的深色激子及其在原子较薄的半导体中的动态
Directly visualizing the momentum forbidden dark excitons and their dynamics in atomically thin semiconductors
论文作者
论文摘要
消除激动品的动力自由度 - 在光激发的半导体中受库仑吸引力绑定的电子孔对，数十年来一直是一个难以捉摸的目标。在原子上薄的半导体中，这种能力可以探测动量禁止的深色激子，这严重影响了提出的光电技术，但无法通过光学技术直接访问。在这里，我们通过对其组成电子进行了光合量，并在时间，动量和能量中解决它们，从而探测了WSE2单层中激动剂的动量状态。我们获得了直接视觉的势头，禁止黑暗激烈的激子，并研究它们的特性，包括它们在能量巨型景观中使用明亮的激子的近乎化学性及其形成途径。这些黑暗的激发子主导着激发的状态分布 - 令人惊讶的发现突出了它们在原子薄的半导体中的重要性。
Resolving the momentum degree of freedom of excitons - electron-hole pairs bound by the Coulomb attraction in a photoexcited semiconductor, has remained a largely elusive goal for decades. In atomically thin semiconductors, such a capability could probe the momentum forbidden dark excitons, which critically impact proposed opto-electronic technologies, but are not directly accessible via optical techniques. Here, we probe the momentum-state of excitons in a WSe2 monolayer by photoemitting their constituent electrons, and resolving them in time, momentum and energy. We obtain a direct visual of the momentum forbidden dark excitons, and study their properties, including their near-degeneracy with bright excitons and their formation pathways in the energy-momentum landscape. These dark excitons dominate the excited state distribution - a surprising finding that highlights their importance in atomically thin semiconductors.
