Experimental Realization of Semiconducting Monolayer Si₂Te₂ Films

Abstract

Abstract The experimental realization of large‐scale, homogeneous semiconducting films with a single‐layer thickness is of major importance for next‐generation devices. Especially in view of the compatibility with state‐of‐the‐art semiconductor technology, Si‐based monolayer crystals are of particular interest. Here, the successful epitaxial growth of monolayer Si 2 Te 2 (MLSi 2 Te 2 ) films on semiconducting Sb 2 Te 3 thin film substrates is reported. High‐quality (1 × 1) ML‐Si 2 Te 2 films with a coverage as high as 95% are obtained as revealed by scanning tunneling microscopy. X‐ray photoelectron spectroscopy confirms the existence of the SiTe bonds in the obtained films. By combining scanning tunneling spectroscopy with density functional theory calculations, the existence of a semiconducting bandgap is demonstrated on the order of 370 meV for the MLSi 2 Te 2 films which reside in an important mid‐infrared spectral range. The results pave the way for practical applications of this novel artificial two‐dimensional material.