Germanene, Ge analogue of graphene, is a near-planar 2D Dirac material stable in a low-buckled graphene-like honeycomb geometry and electronic properties.¹ Graphene’s interesting features lead to booming interest in graphene, and now we are exploring other elemental group IV 2D materials that have graphene-like geometry and electronic properties such as siliecene^2,3, stanene^4,5, germanane (hydrogenated germanene)⁶, and germanene.^7,8,9  Theoretical studies of the 2D honeycomb structured germanene (Ge) have been reported earlier¹⁰, but experimental evidence of germanene synthesis have been reported only in recent years from various groups utilizing ultra-high vacuum (UHV) system.¹¹ A new photon-assisted electrochemical deposition of germanene has been studied, and evidences for germanene formation are found using in situ scanning tunneling microscope (STM) and in situ Raman spectroelectrochemistry. The STM images show that germanium deposited on a single crystalline gold (111) surface exhibit a honeycomb germanene structure. Using in situ surface-enhanced Raman spectroelectrochemistry the germanene peak was reproducibly observed when the germanium deposit was exposed to laser; this peak agrees with the theoretical prediction for the “G-like” mode in germanene and previous experimental result.^12,13

 ADDIN EN.REFLIST 1. Wang, J.; Deng, S.; Liu, Z.; Liu, Z., The rare two-dimensional materials with Dirac cones. National Science Review 2015, 2 (1), 22-39.

2. Grazianetti, C.; Cinquanta, E.; Molle, A., Two-dimensional silicon: the advent of silicene. 2d Materials 2016, 3 (1).

3. Houssa, M.; Dimoulas, A.; Molle, A., Silicene: a review of recent experimental and theoretical investigations. Journal of Physics: Condensed Matter 2015, 27 (25), 253002.

4. Zhu, F.-f.; Chen, W.-j.; Xu, Y.; Gao, C.-l.; Guan, D.-d.; Liu, C.-h.; Qian, D.; Zhang, S.-C.; Jia, J.-f., Epitaxial growth of two-dimensional stanene. Nat Mater 2015, 14 (10), 1020-1025.

5. van den Broek, B.; Houssa, M.; Iordanidou, K.; Pourtois, G.; Afanas'ev, V. V.; Stesmans, A., Functional silicene and stanene nanoribbons compared to graphene: electronic structure and transport. 2d Materials 2016, 3 (1).

6. Bianco, E.; Butler, S.; Jiang, S.; Restrepo, O. D.; Windl, W.; Goldberger, J. E., Stability and Exfoliation of Germanane: A Germanium Graphane Analogue. ACS Nano 2013, 7 (5), 4414-4421.

7. Acun, A.; Zhang, L.; Bampoulis, P.; Farmanbar, M.; Houselt, A. v.; Rudenko, A. N.; Lingenfelder, M.; Brocks, G.; Poelsema, B.; Katsnelson, M. I.; Zandvliet, H. J. W., Germanene: the germanium analogue of graphene. Journal of Physics: Condensed Matter 2015, 27 (44), 443002.

8. Kaloni, T. P.; Schreckenbach, G.; Freund, M. S.; Schwingenschlogl, U., Current developments in silicene and germanene. Physica Status Solidi-Rapid Research Letters 2016, 10 (2), 133-142.

9. Roome, N. J.; Carey, J. D., Beyond Graphene: Stable Elemental Monolayers of Silicene and Germanene. ACS Applied Materials & Interfaces 2014, 6 (10), 7743-7750.

10. Cahangirov, S.; Topsakal, M.; Aktürk, E.; Şahin, H.; Ciraci, S., Two- and One-Dimensional Honeycomb Structures of Silicon and Germanium. Physical Review Letters 2009, 102 (23), 236804.

11. Davila, M. E.; Le Lay, G., Few layer epitaxial germanene: a novel two-dimensional Dirac material. Scientific Reports 2016, 6.

12. Scalise, E.; Houssa, M.; Pourtois, G.; van den Broek, B.; Afanas’ev, V.; Stesmans, A., Vibrational properties of silicene and germanene. Nano Research 2013, 6 (1), 19-28.

13. Tsai, H.-S.; Chen, Y.-Z.; Medina, H.; Su, T.-Y.; Chou, T.-S.; Chen, Y.-H.; Chueh, Y.-L.; Liang, J.-H., Direct formation of large-scale multi-layered germanene on Si substrate. Physical Chemistry Chemical Physics 2015, 17 (33), 21389-21393.