Zero-valent Au, Cu and Sn Intercalation into GeS Nanoribbons: Tailoring Ultrafast Photoconductive Response

摘要

Germanium sulfide (GeS) is a 2D semiconductor with high carrier mobility and a moderate band gap (～1.5 eV for multilayer crystals), which holds promise for high-speed optoelectronics and energy conversion. Here, we use time-resolved THz spectroscopy to investigate how intercalation of Au, Cu, and Sn impacts the photoexcited carrier dynamics and transient photoconductivity of GeS nanoribbons. We find that zero-valent metals affect the photoexcited carrier lifetime and mobility in different ways. Intercalation of GeS with Cu reduces the lifetime of carriers from ～ 120 ps to 60 ps, while Au and Sn intercalation do not. At the same time, intercalation with Cu, Sn and Au significantly enhances the scattering time of photoexcited carriers (～120 fs vs ～65 fs without intercalation), highlighting the potential of zero-valent metal intercalation as a tool for engineering the optoelectronic properties of GeS nanostructures for application in high-speed electronic devices.