A TEAM of researchers from China and the United States has developed a new etching technique for next-generation semiconductor materials, opening fresh possibilities for designing high-performance optoelectronic devices.

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

Perovskite is a mineral with a unique crystal structure and excellent photoelectric properties, making it ideal for next‑generation optoelectronic devices such as solar cells and light‑emitting diodes. However, its crystal lattice is relatively soft and unstable, which makes it difficult for conventional lithography techniques to produce high‑quality, precisely patterned structures.

To address this challenge, the research team developed an ingenious “self‑etching” method that exploits internal crystal stress. As the perovskite crystal grows, stress naturally accumulates. In a carefully designed solvent environment, this stress can be triggered to selectively etch specific regions, creating regular, square‑shaped voids.

The team then used a rapid solvent‑evaporation growth technique to fill these voids with different semiconductor materials, forming continuous, uniform, high‑quality mosaic‑patterned heterostructures within a single crystal.

“This is not just about piecing materials together,” said Zhang Shuchen, a specially appointed professor at 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 suggests that it may be possible to grow densely packed microscopic pixels — each capable of emitting different colors — on an ultrathin material, Zhang said. Such an approach could offer a new materials and design pathway for high‑performance displays.

Beyond displays, the method could enable a range of advanced optoelectronic applications. Precisely patterned lateral heterostructures can be used to fabricate integrated photonic circuits, multicolor light sources, and pixelated sensor arrays on a single thin film. The ability to create abrupt, high‑quality interfaces inside a single crystal also opens opportunities for studying novel quantum and excitonic phenomena in two‑dimensional perovskites.

Several challenges remain before this technique can be widely adopted in manufacturing. Stability under ambient conditions, lead toxicity concerns, and integration with existing semiconductor processing will need to be addressed. The researchers say the next steps include demonstrating working devices based on these mosaic heterostructures and exploring lead‑reduced or lead‑free perovskite compositions to improve environmental compatibility.(SD-Agencies)