Boron-Embedded Cluster Superlattices on Graphene on Ir(111)

Cluster superlattice membranes constitute a novel 2D material, comprising a cluster superlattice sandwiched between a graphene support and an amorphous carbon embedding matrix. They offer a platform for investigating phenomena at the few atom to small cluster level with lateral averaging techniques. The amorphous carbon matrix provides mechanical and thermal stability to the cluster array, but alternative and nonconductive embedding materials are being sought. Such alternative embedding materials might, for instance, be advantageous for use in catalytic reactions and the exploration of charge transport in a cluster array. Here, the embedding of iridium and platinum cluster superlattices in elemental boron is characterized by scanning tunneling microscopy and X-ray photoelectron spectroscopy. The embedding in B preserves the superlattice order and provides mechanical stability comparable to that of amorphous C while maintaining thermal stability with the cluster superlattice order preserved up to 650 K.