Ultrafast scattering process of high-energy carriers plays a key role in the performance of electronics and optoelectronics, and have been studied in several semiconductors. Core-hole clock spectroscopy is a unique technique for providing ultrafast charge transfer information with sub-femtosecond timescale. Here we demonstrate that germanium selenide (GeSe) semiconductor exhibits electronic states-dependent charge delocalization time by resonant photo exciting the core electrons to different final states using hard-x-ray photoemission spectroscopy. Thanks to the experiment geometry and the different orbital polarizations in the conduction band, the delocalization time of electron in high energy electronic state probed from Se 1s is ~470 as, which is three times longer than the delocalization time of electrons located in lower energy electronic state probed from Ge 1s. Our demonstration in GeSe offers an opportunity to precisely distinguish the energy-dependent dynamics in layered semiconductor, and will pave the way to design the ultrafast devices in the future.

高能载流子的超快散射过程在电子学和光电子学的性能中起着关键作用，并已在多种半导体中得到研究。核孔时钟光谱是一种独特的技术，可提供亚飞秒时间尺度的超快电荷转移信息。在这里，我们证明了硒化锗 (GeSe) 半导体通过使用硬 X 射线光电子能谱法将核心电子激发到不同的最终状态，从而表现出电子状态相关的电荷离域时间。由于实验几何形状和导带中不同的轨道极化，从Se 1s探测到高能电子态的电子离域时间是 ~470 as，这是从 Ge 1s探测到的位于低能电子态的电子的离域时间的三倍。我们在 GeSe 中的演示提供了一个机会来精确区分分层半导体中的能量依赖动力学，并将为未来设计超快器件铺平道路。