Transport Properties of Methyl-Terminated Germanane Microcrystallites

Abstract

Germanane is a two-dimensional material consisting of stacks of atomically thin germanium sheets. It’s easy and low-cost synthesis holds promise for the development of atomic-scale devices. However, to become an electronic-grade material, high-quality layered crystals with good chemical purity and stability are needed. To this end, we studied the electrical transport of annealed methyl-terminated germanane microcrystallites in both high vacuum and ultrahigh vacuum. Scanning electron microscopy of crystallites revealed two types of behavior which arise from the difference in the crystallite chemistry. While some crystallites are hydrated and oxidized, preventing the formation of good electrical contact, the four-point resistance of oxygen-free crystallites was measured with multiple tips scanning tunneling microscopy, yielding a bulk transport with resistivity smaller than 1 Ω·cm. When normalized by the crystallite thickness, the resistance compares well with the resistance of hydrogen-passivated germanane flakes found in the literature. Along with the high purity of the crystallites, a thermal stability of the resistance at 280 °C makes methyl-terminated germanane suitable for complementary metal oxide semiconductor back-end-of-line processes.

Temperature dependence of hole mobility in methylated germanane field-effect transistor

“…21) However, most of the experimental reports on GeCH 3 describes the photoelectric 16,17) and chemical properties. 22,23) Regarding electrical properties, there are only one report on resistivity measurements, 24) and no reports on the FET characteristics of GeCH 3 were found.…”

State-of-the-Art 2D and Carbon Nanomaterials in France

“…Another exciting contribution to this issue is the exploration of germanane, a twodimensional material with stacks of atomically thin germanium sheets. The study focused on improving germanane's electrical transport properties to develop atomic-scale devices [5]. The researchers investigated the electrical transport of annealed methylterminated germanane microcrystallites, revealing promising electrical properties suitable for complementary metal oxide semiconductor back-end-of-line processes.…”