Experimental Realization of Atomic Monolayer Si₉C₁₅

Abstract

Monolayer SixCy constitutes an important family of 2D materials that is predicted to feature a honeycomb structure and appreciable bandgaps. However, due to its binary chemical nature and the lack of bulk polymorphs with a layered structure, the fabrication of such materials has so far been challenging. Here, the synthesis of atomic monolayer Si9C15 on Ru (0001) and Rh(111) substrates is reported. A combination of scanning tunneling microscopy (STM), X‐ray photoelectron spectroscopy (XPS), scanning transmission electron microscopy (STEM), and density functional theory (DFT) calculations is used to infer that the 2D lattice of Si9C15 is a buckled honeycomb structure. Monolayer Si9C15 shows semiconducting behavior with a bandgap of ≈1.9 eV. Remarkably, the Si9C15 lattice remains intact after exposure to ambient conditions, indicating good air stability. The present work expands the 2D‐materials library and provides a promising platform for future studies in nanoelectronics and nanophotonics.

Preface: In honor of the 100th Anniversary of Harbin Institute of Technology

“…It is shown in Fig. 3a that Si 9 C 15 siligraphene without loading possesses a direct bandgap of 2.07 eV, which is close to the value of 1.9 eV reported in the previous study [37]. When the size of Si 9 C 15 siligraphene is elongated by 5% or a tensile strain of 5% is applied, the bandgap reduces to 1.55 eV as shown in…”

“…Monolayer Si 9 C 15 was reported to possess a moderate bandgap [37]. To further broaden the application fields of Si 9 C 15 siligraphene in 2D optoelectronic devices, some methods are desired to be developed for modulating its electronic properties.…”

“…Although a great progress has been made in theoretically predicting structures of 2D SiC materials, few of these predicted 2D SiC materials have been synthesized in the laboratory due to the lack of the corresponding experimental synthetic routes. Very recently, Gao et al [37] made a big progress in the synthesis of 2D SiC by successfully fabricating the high-quality Si 9 C 15 siligraphene with the large-scale atomic monolayer. The possible exfoliation of freestanding monolayer Si 9 C 15 from metal substrates together with its good air stability and semiconducting behaviour makes Si 9 C 15 siligraphene appealing for applications in 2D electronics and photonics.…”

Intrinsic auxeticity and mechanical anisotropy of Si9C15 siligraphene

“…Monolayer Si 9 C 15 has been reported to possess a moderate bandgap. 37 To further broaden the application fields of Si 9 C 15 siligraphene in 2D optoelectronic devices, some methods are desired to be developed for modulating its electronic properties. Strain engineering is one of the most common means to modify the electronic structures of 2D materials.…”

“…29,[33][34][35][36] Although great progress has been made in theoretically predicting the structures of 2D SiC materials, few of these predicted 2D SiC materials have been synthesized in the laboratory due to the lack of the corresponding experimental synthetic routes. Very recently, Gao et al 37 made big progress in the synthesis of 2D SiC by successfully fabricating high-quality Si 9 C 15 siligraphene with a large-scale atomic monolayer. The possible exfoliation of freestanding monolayer Si 9 C 15 from metal substrates together with its good air stability and semiconducting behaviour makes Si 9 C 15 siligraphene appealing for applications in 2D electronics and photonics.…”