(Yicai) Jan. 19 -- A team of researchers from China and the United States has invented a new etching technique for next-generation semiconductor materials, opening up fresh possibilities for designing high-performance optoelectronic devices.

Researchers from the University of Science and Technology of China, ShanghaiTech University, and the US’ Purdue University have for the first time achieved the controllable preparation of mosaic lateral heterostructures in two-dimensional lead halide perovskites, according to the findings published in the scientific journal Nature on Jan. 14.

The mineral perovskite has an unique crystal structure with excellent photoelectric properties which makes it ideal for next-generation optoelectronic devices such as solar cells and light-emitting diodes. However, its crystal structure is soft and unstable, making it difficult for conventional lithography techniques to achieve high-quality and precise patterns.

To tackle this, the research team came up with an ingenious “self-etching” method that uses internal crystal stress. As the perovskite crystal grows, it naturally builds stress inside. In a carefully designed solvent environment, this stress can be triggered to etch specific spots, creating regular, square-shaped holes.

The research team then used a rapid solvent evaporation growth technique to fill these holes with different semiconductor materials, forming continuous, even and high-quality mosaic-patterned heterostructures in a single crystal.

“This is not just about piecing materials together,” said Zhang Shuchen, a specially-appointed professor from the University of Science and Technology of China and one of the study’s corresponding authors. “We are guiding the crystal itself to form continuous lateral heterostructures within it.”

The breakthrough means that in future, it could be possible to grow densely packed tiny pixels, which are each capable of emitting different colors, on an extremely thin material, Zhang said. This could offer a new material and design approach for high-performance displays.

Editor: Kim Taylor