Dry Transfer Method Achieves Breakthrough in Wafer-Scale 2D Semiconductor Flexible Integration

Flexible Electronics Sees Key Technological Breakthrough

On May 27, Westlake University announced that Professor Kong Wei's team at the School of Engineering has achieved a major advance in flexible semiconductor integration — successfully realizing high-quality integration of wafer-scale single-crystal molybdenum disulfide (MoS₂) thin films on flexible substrates, marking the first time single-crystal 2D semiconductor transfer integration technology has been advanced from the traditional 'wet' approach to a 'dry' approach. The research has been published in the top international journal Nature Electronics, signaling a critical step forward in the fabrication of high-performance flexible electronic devices.

Why Is 'Dry Transfer' So Important?

2D semiconductor materials, particularly transition metal dichalcogenides such as molybdenum disulfide, are considered ideal candidates for next-generation flexible electronic devices due to their atomic-scale thickness, excellent electrical properties, and inherent mechanical flexibility. However, transferring these materials from growth substrates to flexible substrates with high quality has remained a core technical bottleneck constraining the field's development.

Traditional 'wet transfer' processes rely on chemical solutions to etch or peel growth substrates. While this approach has yielded some results at the laboratory scale, it suffers from numerous hard-to-overcome problems: chemical residues contaminate the film surface, films are prone to wrinkling and cracking during transfer, and large-area uniformity is difficult to guarantee. All of these factors severely compromise the electrical performance and consistency of devices.

By contrast, 'dry transfer' technology avoids the introduction of chemical solutions, enabling film delamination and transfer in a much cleaner environment. The wafer-scale dry transfer achieved by Kong Wei's team indicates that this technology now has the potential to move from the laboratory toward scalable manufacturing.

Wafer-Scale Single-Crystal Films: From 'Small Fragments' to 'Large Areas'

Another important highlight of this research lies in the two keywords 'wafer-scale' and 'single-crystal.' In previous studies, the transfer of 2D semiconductor materials was mostly limited to small-area samples ranging from micrometers to millimeters, and the films were often polycrystalline. The presence of grain boundaries significantly reduces key electrical parameters such as carrier mobility.

Kong Wei's team successfully achieved the complete transfer of single-crystal MoS₂ thin films at the wafer scale, meaning the transferred film maintains a high degree of lattice uniformity across the entire wafer, fundamentally eliminating the negative impact of grain boundaries on device performance. This achievement lays the material foundation for building large-scale, high-performance integrated circuit arrays on flexible substrates in the future.

Broad Application Prospects for Flexible Electronics

High-performance flexible electronic devices hold broad application prospects across multiple frontier fields. In wearable health monitoring, flexible sensors can conform to human skin for real-time physiological signal acquisition. In flexible displays, the performance of foldable screens is expected to improve further. In the Internet of Things and smart packaging, ultra-thin flexible chips will enable ubiquitous connectivity. Additionally, in AI edge computing scenarios, flexible neuromorphic devices also demonstrate unique advantages.

Previously, flexible electronics largely relied on organic semiconductors or amorphous silicon materials, with performance far below that of traditional rigid chips. The introduction of 2D semiconductors promises to fundamentally bridge the gap between flexibility and high performance, and this breakthrough in dry transfer technology is a key link in realizing that vision.

Outlook: How Far from Lab to Industrialization?

Although this achievement is exciting, numerous challenges remain between laboratory validation and industrial application. Issues such as the yield and reproducibility of wafer-scale transfer, compatibility with existing semiconductor manufacturing processes, and the long-term stability of flexible devices all need to be addressed in subsequent research.

Nevertheless, the results published by Kong Wei's team in Nature Electronics have undoubtedly injected strong confidence into the entire field. As the full technology chain — including 2D semiconductor material growth, transfer, and device fabrication — continues to mature, the pace at which high-performance flexible electronics moves from concept to reality is accelerating significantly. This original breakthrough from a Chinese research team once again demonstrates China's cutting-edge competitiveness in the field of novel semiconductor materials and devices.