Vapor Phase Growth and Grain Boundary Structure of Molybdenum Disulfide Atomic Layers

TL;DR

This paper presents a controlled vapor phase synthesis method for molybdenum disulfide atomic layers, analyzing their growth mechanisms, grain boundary structures, and electrical properties, demonstrating high-quality, scalable production for nanoelectronic applications.

Contribution

It introduces a nucleation-controlled strategy for large-area monolayer and few-layer molybdenum disulfide films and investigates their atomic structure and electrical performance.

Findings

Successful synthesis of large-area, high-quality molybdenum disulfide layers.

Detailed understanding of nucleation, growth, and grain boundary formation.

Enhanced electrical properties linked to grain boundary control.

Abstract

Single layered molybdenum disulfide with a direct bandgap is a promising two-dimensional material that goes beyond graphene for next generation nanoelectronics. Here, we report the controlled vapor phase synthesis of molybdenum disulfide atomic layers and elucidate a fundamental mechanism for the nucleation, growth, and grain boundary formation in its crystalline monolayers. Furthermore, a nucleation-controlled strategy is established to systematically promote the formation of large-area single- and few-layered films. The atomic structure and morphology of the grains and their boundaries in the polycrystalline molybdenum disulfide atomic layers are examined and first-principles calculations are applied to investigate their energy landscape. The electrical properties of the atomic layers are examined and the role of grain boundaries is evaluated. The uniformity in thickness, large grain sizes, and excellent electrical performance of these materials signify the high quality and scalable synthesis of the molybdenum disulfide atomic layers.