According to a Nature news article cited below (info-box "The rise of silicone"), six independent papers were published reporting successful epitaxial formation of silicene. Does anyone know which those were? I am just able to find the following two papers:
Fleurence, A., R. Friedlein, T. Ozaki, H. Kawai, Y. Wang, Y. Yamada-Takamura (2012). "Experimental evidence for epitaxial silicene on diboride thin films". Physical Review Letters 108(24)
Vogt, P., P. De Padova, C. Quaresima, J. Avila, E. Frantzeskakis, M.C. Asensio, A. Resta, B. Ealet, G. Le Lay (2012). "Silicene: compelling experimental evidence for graphenelike two-dimensional silicon". Physical Review Letters 108(15)
Nature (2015). "Graphene’s cousin silicene makes transistor debut". Nature news article. URL: http://www.nature.com/news/graphene-s-cousin-silicene-makes-transistor-debut-1.16839
Does anyone know where to find the other four?