Scientists have developed a new way to grow high-quality semiconductor films at low temperatures, a breakthrough that could make it easier to build the next generation of AI chips, ultra-low-power electronics, and advanced light-based devices.
The research was led by Professor Joonki Suh and colleagues at the Korea Advanced Institute of Science and Technology (KAIST), working with researchers from Hanyang University in South Korea and Rice University in the United States.
The study was published in the journal Science Advances.
Modern electronic devices often rely on combining different materials, each with a special job.
To make these devices work well, engineers need to stack these materials together without damaging them or the tiny boundary where they meet. Even small defects at these interfaces can reduce device performance.
One group of materials attracting growing attention is called van der Waals materials. These are made of extremely thin layers of atoms that are only weakly connected to each other.
Because of this, different materials can be stacked together almost like sheets of paper while keeping their surfaces clean. Scientists believe these materials could play a major role in future semiconductor technologies, especially for artificial intelligence and energy-saving electronics.
However, there has been a major challenge. The surfaces of van der Waals materials are chemically stable, making it difficult for new semiconductor layers to grow in an organized way. The problem becomes even harder at lower temperatures because atoms tend to settle randomly instead of lining up with the crystal structure underneath. Random growth reduces the quality and performance of semiconductor devices.
To solve this problem, the researchers developed a new version of atomic layer deposition (ALD), a manufacturing process that builds extremely thin films one atomic layer at a time.
Their method allows tellurium-containing molecules, known as precursors, to move freely across the surface before attaching. This gives the molecules time to find the most stable positions, allowing them to grow into a well-organized crystal instead of a disordered layer.
The team focused on tellurium because it has excellent electrical and optical properties. It can conduct electricity differently depending on direction and interacts strongly with light, making it useful for future devices such as photodetectors, light-emitting diodes (LEDs), and advanced semiconductor components.
Using their new approach, the researchers successfully grew tellurium films in a single crystal direction at only 150°C (302°F). This type of crystal growth, known as epitaxy, allows the new layer to follow the atomic arrangement of the material underneath. A simple way to imagine this is stacking bricks neatly in straight rows instead of placing them randomly. A more orderly structure helps electricity flow more efficiently and improves device performance.
The researchers also showed that the method works on several different van der Waals materials, including tungsten diselenide, molybdenum disulfide, rhenium diselenide, and mica. This suggests the technique could be widely used rather than being limited to just one type of material.
To demonstrate its practical value, the team used the newly grown films to build working transistors and optoelectronic devices that can control, detect, or emit light. This shows the technology is not only useful for producing high-quality materials in the laboratory but also has strong potential for manufacturing real electronic devices.
Professor Suh said the study is the first to show that high-quality semiconductor films can be grown on van der Waals materials at low temperatures without damaging the underlying layers.
The researchers believe this manufacturing method could become an important platform for combining many different next-generation semiconductor materials onto a single chip, helping pave the way for faster, more efficient electronics in the future.
