Autonomous synthesis of thin film materials with pulsed laser deposition enabled by in situ spectroscopy and automation

TL;DR

This paper presents an autonomous system combining pulsed laser deposition, in situ spectroscopy, and machine learning to rapidly synthesize and optimize thin film materials, significantly accelerating materials discovery.

Contribution

It introduces a novel autonomous workflow integrating real-time spectroscopy and AI for PLD-based thin film synthesis, enabling rapid exploration of large parameter spaces.

Findings

10x increase in throughput for ultrathin WSe2 films

Autonomous discovery of growth windows using Bayesian optimization

Sampled only 0.25% of the parameter space for process-property mapping

Abstract

Synthesis of thin films has traditionally relied upon slow, sequential processes carried out with substantial human intervention, frequently utilizing a mix of experience and serendipity to optimize material structure and properties. With recent advances in autonomous systems which combine synthesis, characterization, and decision making with artificial intelligence (AI), large parameter spaces can be explored autonomously at rates beyond what is possible by human experimentalists, greatly accelerating discovery, optimization, and understanding in materials synthesis which directly address the grand challenges in synthesis science. Here, we demonstrate autonomous synthesis of a contemporary 2D material by combining the highly versatile pulsed laser deposition (PLD) technique with automation and machine learning (ML). We incorporated in situ and real-time spectroscopy, a high-throughput methodology, and cloud connectivity to enable autonomous synthesis workflows with PLD. Ultrathin WSe2 films were grown using co-ablation of two targets and showed a 10x increase in throughput over traditional PLD workflows. Gaussian process regression and Bayesian optimization were used with in situ Raman spectroscopy to autonomously discover two distinct growth windows and the process-property relationship after sampling only 0.25% of a large 4D parameter space. Any material that can be grown with PLD could be autonomously synthesized with our platform and workflows, enabling accelerated discovery and optimization of a vast number of materials.