High-speed optical imaging plays an important role in fields ranging from scientific research and industrial inspection to intelligent sensing and machine vision. Capturing ultrafast events requires photodetectors that can respond quickly while maintaining high sensitivity and low noise. However, improving response speed often comes at the expense of signal quality, creating a long-standing challenge for next-generation imaging technologies.
To address this issue, researchers developed a new semimetal-semiconductor heterostructure based on NbSe 2 and WSe 2 . By engineering the interface between the two materials, the team created an optimized interfacial energy barrier that accelerates charge separation while suppressing dark current.
The researchers also introduced band curvature as a new framework for understanding how interfacial band modulation affects device performance. This approach provides a unified way to describe the relationship between interfacial energy barriers, carrier transport, and photoresponse behavior in van der Waals heterostructures.
Using this strategy, the NbSe 2 /WSe 2 device achieved both low dark current and rapid photoresponse, overcoming the traditional trade-off between sensitivity and speed. The improved performance enabled high-speed optical imaging with enhanced fidelity.
Beyond demonstrating a high-performance photodetector, the study offers new insights into interface engineering in two-dimensional materials. The findings provide a promising route for developing next-generation optoelectronic devices for ultrafast imaging, intelligent vision systems, and advanced sensing applications.
Science Bulletin