▎ 摘　　要

By combining high-resolution photoelectron spectroscopy and ab initio calculations, we show that carbon nanoislands formed during the growth of a long-range ordered graphene layer on Ir(111) assume a peculiar domelike shape. The understanding of the unusual growth mechanism of these C clusters, which represent an intermediate phase between the strongly coupled carbidic carbon and a quasi-free-standing graphene layer, can provide information for a rational design of graphenelike systems at the nanoscale.