Deep-Learning-Enabled Fast Optical Identification and Characterization of Two-Dimensional Materials

TL;DR

This paper presents a neural network approach for rapid, accurate optical identification and characterization of 2D materials, leveraging deep features and transfer learning to enhance nanomaterials research.

Contribution

It introduces a neural network-based method for real-time 2D material identification and property prediction, with transfer learning for broader applications.

Findings

High prediction accuracy for material and thickness identification

Deep graphical features extracted correlate with physical properties

Transfer learning enables adaptation to new 2D materials

Abstract

Advanced microscopy and/or spectroscopy tools play indispensable role in nanoscience and nanotechnology research, as it provides rich information about the growth mechanism, chemical compositions, crystallography, and other important physical and chemical properties. However, the interpretation of imaging data heavily relies on the "intuition" of experienced researchers. As a result, many of the deep graphical features obtained through these tools are often unused because of difficulties in processing the data and finding the correlations. Such challenges can be well addressed by deep learning. In this work, we use the optical characterization of two-dimensional (2D) materials as a case study, and demonstrate a neural-network-based algorithm for the material and thickness identification of exfoliated 2D materials with high prediction accuracy and real-time processing capability. Further analysis shows that the trained network can extract deep graphical features such as contrast, color, edges, shapes, segment sizes and their distributions, based on which we develop an ensemble approach topredict the most relevant physical properties of 2D materials. Finally, a transfer learning technique is applied to adapt the pretrained network to other applications such as identifying layer numbers of a new 2D material, or materials produced by a different synthetic approach. Our artificial-intelligence-based material characterization approach is a powerful tool that would speed up the preparation, initial characterization of 2D materials and other nanomaterials and potentially accelerate new material discoveries.