Xinhua News Agency, Hefei, January 15th (Reporter Dai Wei) From the Chinese University of Science and Technology, it has been learned that Professor Shuchen Zhang's team at USTC, in collaboration with researchers from Purdue University in the United States and Shanghai Tech University, has made significant progress in the field of new semiconductor materials. The research team has achieved controllable construction of "mosaic" heterostructures with in-plane programmability and atomic-level flatness for the first time in two-dimensional ionic soft lattice materials, opening up a new path for the development of high-performance light-emitting and integrated devices. The related achievements were published online on January 15th in the international authoritative academic journal "Nature".
In the field of semiconductors, the ability to precisely construct heterostructures in the plane of the material is key to exploring novel physical properties, developing new devices, and promoting device miniaturization. However, ion-type soft lattice semiconductors, such as two-dimensional halide perovskites, have soft and unstable crystal structures. Traditional photolithography processing techniques often cause excessive reactions that destroy the material structure, making it difficult to achieve high-quality lateral hetero-integration. How to achieve high-quality, controllable epitaxial lateral heterostructures in these materials is an important scientific challenge in this field.
Facing this challenge, the research team took a unique approach and innovatively proposed and developed a new method of guiding internal stress within the crystal for "self-etching". Researchers found that two-dimensional perovskite single crystals naturally accumulate internal stress during growth. The team cleverly designed a mild ligand-solvent micro-environment, which can selectively activate and utilize these internal stresses, guiding the single crystal to undergo controlled "self-etching" at specific locations, thereby forming regular square hole structures. Subsequently, by using rapid epitaxial growth technology, different types of semiconductor materials were precisely filled back, finally constructing a high-quality "mosaic" heterostructure with continuous lattice and atomically flat interfaces within a single wafer.
"This new processing method does not rely on 'assembling' different materials, but instead guides the crystal itself to perform precise 'self-assembly' within a single intact crystal," explained Zhang Shuchen. "This means that in the future, we may be able to directly 'grow' densely arranged, small pixel points that emit different colors of light on an extremely thin material, providing a new alternative material system and design concept for the development of high-performance light-emitting and display devices."
Researchers stated that this study achieved the first high-quality, designable construction of lateral heterostructures in a two-dimensional ionic material system, breaking through the limitations of traditional processes. The new paradigm of controlling internal stress and dynamics in crystals demonstrated by this research enables the programmable evolution of functional structures within a single crystal, providing a new platform for studying idealized interface physics, and opening up new paths for the integration and device fabrication of low-dimensional materials.
Original: toutiao.com/article/7595417898932240948/
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