Rapid, versatile, and reliable metrology for multi-layer transition metal dichalcogenide thin films using atomic force microscopy to investigate surface grain distributions

Abstract

Molybdenum disulfide (MoS2) has garnered significant attention among 2D materials, demonstrating great potential for electronics and optoelectronics. Although numerous growth techniques have been explored, a definitive solution for large-area film fabrication remains elusive. Moreover, comparing thin films obtained through different techniques is not straightforward. Particularly, analyzing grain size across samples is challenging, making it difficult to clearly correlate growth conditions with the resulting crystal structure. In this Letter, we developed an approach based on atomic force microscopy (AFM) morphology measurements to analyze nanograins in large-area thin films obtained through relevant growth techniques such as chemical vapor deposition and sputter deposition followed by pulsed laser annealing. To address the challenges in comparing thin films grown by different methods, we propose a robust approach based on statistical grain analysis. By combining well-established investigation tools, such as AFM, with advanced watershed-segmentation algorithms, we demonstrate a reliable method for identifying grains and grain boundaries. This approach allows for a robust and quantitative comparison of film morphology across different growth conditions, providing a crucial benchmark for evaluating and differentiating various growth methods.