In-plane growth of large ultra-thin SnS2 nanosheets by tellurium-assisted chemical vapor deposition

Abstract

Two-dimensional (2D) SnS₂ has attracted significant attention as a potential candidate for modern electronics and optoelectronics. However, the in-plane growth of large ultra-thin SnS₂ nanosheets (NSs) still remains a great challenge. In this study, we successfully synthesized in-plane SnS₂ NSs with sizes up to 280 μm on SiO₂/Si substrates via Te-assisted CVD. On mixing SnO₂ and Te, SnO₂ reacted with Te to form a Sn–Te eutectic mixture with low melting point, which enhanced the volatilization of the SnO₂ precursor. On increasing the substrate temperature from 500 °C to 600 °C, the shape of the SnS₂ NSs varied from truncated triangle or hexagonal (HEX) to semi-HEX. High temperature enhanced the migration of the SnS₂ adatoms on the substrates and over the edge of the SnS₂ NSs; thus, the size of the SnS₂ NSs increased with temperature. Further discussion indicates that the truncated triangular shape mainly formed for the substrate breaks the intrinsic sixfold symmetry into three-fold symmetry. The systematic investigation will significantly increase our understanding of the synthesis of 2D materials via Te-assisted CVD.