Fundamental dynamic processes at the electronic contact interface, such as carrier injection and transport, become pivotal and significantly affect device performance. Time-resolved photoemission electron microscopy (TR-PEEM) with high spatiotemporal resolution provides unprecedented abilities of imaging the electron dynamics at the interface. Here, we implement TR-PEEM to investigate the electron dynamics at a coplanar metallic 1 T′-MoTe₂/semiconducting 2H-MoTe₂ heterojunction. We find the non-equilibrium electrons in the 1 T′-MoTe₂ possess higher energy than those in the 2H-MoTe₂. The non-equilibrium photoelectrons collapse and relax to the lower energy levels in the order of picoseconds. The photoexcited electrons transfer from 1 T′-MoTe₂ to 2H-MoTe₂ with at a rate of ~0.8 × 10¹² s⁻¹ (as fast as 1.25 ps). These findings contribute to our understanding of the behavior of photoexcited electrons in heterojunctions and the design of in-plane optoelectronic devices.

电子接触界面上的基本动态过程（例如载流子注入和传输）变得至关重要，并严重影响器件性能。具有高时空分辨率的时间分辨光电子显微镜（TR-PEEM）提供了前所未有的在界面上成像电子动力学的能力。在这里，我们实现TR-PEEM，以研究共面金属1 T'-MoTe ₂ /半导体2H-MoTe ₂异质结处的电子动力学。我们发现1 T'-MoTe _2中的非平衡电子具有比2H-MoTe _2中的非平衡电子更高的能量。非平衡光电子崩溃并松弛到皮秒级的较低能级。光激发电子以〜0.8 ×10 ¹²  s ^-1（最快1.25 ps）的速率从1 T'-MoTe ₂转移到2H-MoTe ₂。这些发现有助于我们理解异质结中光激发电子的行为以及平面内光电器件的设计。