Reviewed by Lexie CornerFeb 24 2025
A research team at Pohang University of Science and Technology has developed a method for the uniform and efficient synthesis of perovskite nanocrystals, a next-generation semiconductor material. The study was published in ACS Nano.
Image Credit: Pohang University of Science and Technology
This study represents a step toward addressing the limitations of traditional synthesis methods and accelerating the commercialization of optoelectronic devices such as solar cells and light-emitting diodes.
The research was conducted by Professors Young-Ki Kim and Yong-Young Noh of the Department of Chemical Engineering at Pohang University of Science and Technology (POSTECH), Ph.D. candidate Jun-Hyung Im, Dr. Myeonggeun Han of Samsung Electronics, and Dr. Jisoo Hong of Princeton University.
The quantum confinement effect enables precise control of particle size and shape, making perovskite nanocrystals (PNCs) suitable for applications in next-generation solar cells and high-efficiency displays.
However, conventional PNC synthesis techniques, such as hot-injection and ligand-assisted reprecipitation (LARP), require high temperatures and complex experimental setups, limiting their ability to produce uniformly sized and shaped particles. As a result, additional processing steps are needed to achieve the desired properties, reducing productivity and limiting industrial applications.
The POSTECH research team developed a synthesis method that incorporates liquid crystal (LC) as an antisolvent in the LARP process to achieve precise control over PNC size and shape. LC is an intermediate phase of matter that exhibits molecular ordering similar to crystals while maintaining the fluidity of liquids.
During the LC phase, molecules align in a preferred orientation, leading to elasticity. When an external force is applied to an LC medium, the molecules undergo reorientation, generating significant elastic strain.
By replacing the antisolvent in the LARP method with LC while maintaining other synthesis conditions, the researchers could regulate PNC growth. When the PNCs reached the extrapolation length (ξ) of LCs, their growth was constrained by the elastic strains of the LC molecules. This approach allowed for the mass production of uniformly sized PNCs without additional purification steps.
The study also found that interactions between surface-binding ligands and LC molecules are critical in reducing surface defects. The rod-like structure of LC molecules facilitates the dense arrangement of ligands between them. As a result, ligands bind more tightly to the PNC surface during nanocrystal formation, minimizing surface imperfections and enhancing luminescence properties.
The synthesis method developed by our research team is highly compatible with existing synthesis techniques, such as ligand exchange and microfluidic synthesis, and will enhance the performance of various optoelectronic devices, including LEDs, solar cells, lasers, and photodetectors. This technology enables the large-scale production of uniform, high-performance nanocrystals at room temperature, and we anticipate it will help accelerate the commercialization of nanocrystal-based optoelectronic devices.
Young-Ki Kim, Professor, Pohang University of Science and Technology
The Basic Research Program (Hanwoomul-Phagi Basic Research) and the Pioneer Program for Promising Future Convergence Technology of the National Research Foundation of Korea (NRF) funded the study.
Journal Reference:
Im, J.-H., et al. (2025) Controlled Synthesis of Perovskite Nanocrystals at Room Temperature by Liquid Crystalline Templates. ACS Nano. doi.org/10.1021/acsnano.4c13217.