SKKU Research Team Uncovers Chemical Pathway to Advance Next-Generation Infrared III–V Nanocrystals

A groundbreaking advancement has been achieved by a research team led by Professor Sohee Jeong at Sungkyunkwan University, unveiling a critical chemical mechanism that paves the way for the controlled synthesis of III–V semiconductor quantum dots. These materials are poised to transform next-generation infrared technologies, which are indispensable in applications ranging from autonomous vehicle sensors and smart environmental sensing systems to night-vision imaging devices and short-wave infrared optoelectronics. This pioneering breakthrough represents a significant leap towards the scalable and reproducible fabrication of high-performance infrared semiconductors, addressing long-standing challenges in the field.

The collaborative study, carried out jointly with Professor Maksym V. Kovalenko’s laboratory at ETH Zurich, was published in the prestigious Journal of the American Chemical Society, highlighting a strategic chemical understanding behind the heavy-pnictogen reduction process used to synthesize III–V nanocrystals. The research, titled “Metal–Amide Chemistry Enables Controlled Heavy-Pnictogen Reduction for Colloidal III–V Nanocrystal Synthesis,” elucidates an untapped facet of precursor chemistry fundamental to the formation of indium arsenide (InAs) and indium antimonide (InSb) quantum dots.

With infrared technology increasingly integral to modern life—particularly for nighttime object recognition in autonomous vehicles and smart home applications—the demand for safer, efficient, and scalable infrared semiconductor materials is surging. III–V quantum dots like InAs and InSb boast superior optical properties in the infrared spectrum, alongside a less toxic profile, circumventing the environmental and health concerns associated with lead (Pb) and mercury (Hg)-based alternatives. However, the synthesis of these heavy-pnictogen-containing compounds has remained hindered by the unavailability of practical precursor systems and a lack of comprehensive insight into their chemical behavior.

Professor Jeong’s team confronted this barrier by innovatively decoupling the activation phase of heavy-pnictogen(III) precursors from the quantum dot nucleation process. This separation allowed unprecedented observation and control over the reduction dynamics of arsenic and antimony precursors, revealing how these species achieve reactivity before culminating in crystalline nanostructures. Through careful thermal regulation and precursor environment manipulation, the researchers accessed intermediate states in which heavy-pnictogen species are partially reduced but remain primed for quantum dot growth.

Fundamentally, the investigation uncovered that metal–amide complexes—entities formed via the reaction of metal–alkyl reagents with primary amines—serve as pivotal agents mediating the controlled reduction of heavy-pnictogen(III) precursors. The team demonstrated that upon heating, these metal–amide species undergo amide-to-imine oxidation, a thermally activated transformation that, in turn, facilitates the reduction of arsenic and antimony centers in the precursor molecules. By tuning the reaction temperature and choosing appropriate metal-cation environments, this process can be finely managed to yield precursors with tailored levels of reduction, optimizing them for subsequent III–V nanocrystal formation.

This mechanistic revelation signifies a paradigm shift from empirical, trial-and-error synthesis methods towards a rational, chemistry-driven design principle. Traditional approaches often involve mixing all chemical components simultaneously and iteratively adjusting conditions to achieve desired nanocrystal properties. In stark contrast, the newfound methodology enables the pre-formation of customized precursors with known reactivities, which can then be employed in a controlled manner to dictate nanocrystal growth precisely. This level of control offers unprecedented tunability and reproducibility, essential for the advancement of nanomaterials science.

Applying their approach, the researchers successfully synthesized high-quality InAs and InSb quantum dots without the need for additional reducing agents during the growth phase. This represents a notable simplification of synthesis protocols and enhances their compatibility across various fabrication techniques such as heat-up, hot-injection, and continuous-injection methods. Consequently, this versatility holds promise for scaling up production while maintaining fine control over nanocrystal size, composition, and optical characteristics—parameters critical for device integration.

Beyond the technical accomplishment, the research illuminates underlying chemical principles concealed within the complex domain of semiconductor synthesis. By unraveling the role of metal–amide chemistry in precursor reduction, it demystifies the pathways leading to the formation of technologically vital III–V nanocrystals. Such insights enable a more fundamental understanding that can be leveraged for designing next-generation materials tailored to the demanding specifications of emerging optical and sensing devices.

The implications of this discovery extend well into the future of infrared sensing and imaging technologies. III–V quantum dots synthesized through this controlled reduction method are anticipated to enhance device performance, reliability, and safety. For example, autonomous vehicles will benefit from more efficient and sensitive infrared detectors, potentially improving navigation and obstacle detection at night or under challenging environmental conditions. Similarly, smart sensors equipped with these advanced materials will provide superior responsiveness in security and health monitoring applications.

Moreover, the avoidance of hazardous heavy metals like lead and mercury aligns with increasingly stringent environmental regulations and consumer safety standards, making these quantum dots attractive for widespread commercial adoption. The ability to produce these materials via scalable, reproducible synthetic routes further accelerates their integration into practical devices, fostering innovation across multiple industries.

This seminal work was made possible through robust support from the Ministry of Science and ICT, the National Research Foundation of Korea, Samsung Electronics, and complementary research infrastructure programs. It stands as a testament to the power of international scientific collaboration and multidisciplinary inquiry in solving complex materials chemistry challenges and advancing quantum dot technology towards real-world applications.

The research produced by Professor Jeong’s group, with contributions from international partners, sets a new standard for the informed chemical synthesis of heavy-pnictogen-based III–V nanocrystals. It bridges critical gaps between precursor chemistry, reaction engineering, and nanomaterial performance, charting a clear path for innovation in infrared optoelectronics and beyond. As these insights are integrated into broader scientific and industrial frameworks, the influence of this study will likely resonate through the next decades of semiconductor research and development.

In sum, the controlled reduction of heavy-pnictogen precursors via metal–amide chemistry constitutes a transformative advance, not only enriching the fundamental understanding of nanocrystal synthesis but also enabling the practical realization of high-performance, safer III–V quantum dot materials essential for the technological landscape of the future.

News Publication Date: May 4, 2026

Web References: 10.1021/jacs.6c02928

Keywords

III–V semiconductor quantum dots, heavy-pnictogen reduction, metal–amide chemistry, indium arsenide, indium antimonide, nanocrystal synthesis, infrared materials, optoelectronics, autonomous driving sensors, precursor design, chemical mechanism, scalable nanomaterials