In situ spectroelectrochemical formation of germanene

Germanene is a germanium allotrope similar to graphene. Unlike graphene, germanene features a low-buckled structure, because the Ge-Ge bond in germanene has both sp2 and sp3 hybridization. However, germanene still features Dirac cones in its band structure, thus electrons near Fermi level behave as massless particles; resulting in ultra-high carrier mobility. Experimental formation of germanene has been reported starting 2014, but most of the reports so far have been limited to UHV environment. However, electrochemical formation of germanene in aqueous media, primarily studied using in situ STM, has been recently reported by the presenter’s group.1, 2 Yet, reproducible direct spectroscopic measurement of electrochemically formed germanene has not been achieved. To establish a method to further study germanene formation, in situ SERS spectroelectrochemical studies were performed and evidences of crystalline free standing germanene development were observed.

1. Ledina, M. A.; Bui, N.; Liang, X.; Kim, Y.-G.; Jung, J.; Perdue, B.; Tsang, C.; Drnec, J.; Carlà, F.; Soriaga, M. P.; Reber, T. J.; Stickney, J. L., Electrochemical Formation of Germanene: pH 4.5. Journal of The Electrochemical Society 2017, 164, D469-D477.
2.  Ledina, M.; Liang, X.; Kim, Y.-G.; Jung, J.; Perdue, B.; Tsang, C.; Soriaga, M.; Stickney, J. L., (Invited) Investigations into the Formation of Germanene Using Electrochemical Atomic Layer Deposition (E-ALD). ECS Transactions 2015, 66, 129-140.