多彩的纳米材料——2023年度诺贝尔化学奖解读

The multi-color nanomaterials——A summary of the Nobel Prize in Chemistry 2023

2023年诺贝尔化学奖于10月4日授予了来自美国麻省理工学院Moungi G.Bawendi教授、哥伦比亚大学Louis E.Brus教授和俄罗斯科学家Alexei I.Ekimov,获奖理由是对量子点的发现和合成作出的突出贡献.正如瑞典皇家科学院称:今年诺贝尔化学奖的研究成果为纳米科技“播下了重要的种子”(“The Nobel Prize in Chemistry 2023:They planted an important seed for nanotechnology”).

The Nobel Prize in Chemistry 2023 was awarded to three scientists for their work in the discovery and synthesis of quantum dots:Moungi G.Bawendi from Massachusetts Institute of Technology,Louis E.Brus from Columbia University and Alexei I.Ekimov from Nanocrystals Technology Inc.As the praise from the Royal Swedish Academy of Sciences:they planted an important seed for nanotechnology.In this summary,the backgrounds and scientific significance of these researches and quantum dots are discussed.Quantum dots(QDs)with sizes ranging from~1 to 10 nm are constructed by hundreds to a few thousand atoms.As the size of QDs becomes smaller,quantum confinement enhances the effective bandgap,inducing an obvious blue shift of the emission and absorption spectra.An electron excited across the bandgap processes strong interactions with valence band hole.Spin-exchange coupling and Coulomb effects could generate increased confined electron-hole excitons.In QDs,the close proximity in charge carriers leads to enhanced many-body results that will affect their optical properties.“Quantum dots have various fascinating and unique properties.Significantly,they have different colors depending on their size,”said Johan Aqvist,chair of the Nobel Committee for Chemistry.Firstly,Alexei I.Ekimov performed pioneering study of quantum confinement effects of QDs in glass.He found that the copper chloride nanocrystals(2−30 nm)could be obtained through controlling the reaction temperature and time in molten glass.The size-dependent absorption spectra further demonstrated the quantum confinement effects in this system.Louis E.Brus was the first researcher in the world to verify size-dependent quantum effects in nanoparticles floating freely in liquid phase.In their solar energy experiments,the QDs with small size and high specific surface area could strengthen the reaction efficiency.Moungi G.Bawendi proposed a relatively simple synthetic approach to produce high-quality QDs.In this synthesis,they controlled the rapid injection of organometallic reagents into coordinating solvent for realizing homogeneous nucleation.During the past decades,a serial of QDs has been designed through various reaction conditions,such as cadmium selenide(CdSe),cadmium sulfide(CdS),cadmium telluride(CdTe),zinc sulfide(ZnS),indium arsenide(InAs),and indium phosphide(InP),etc.QDs have attracted impressive attentions in the last decades due to their various advantages and characteristics.Many kinds of QDs have been produced and supplied in the form of industrial products.In the past decades,taking advantages of strong emission and robust photostability,scientists have made an extensive effort to establish a QDs system for various biological and biomedicine applications.QDs-based light emitting diodes(QLEDs)have gained great attentions in the virtue of their narrow half-peak width and stable optical performance.Scientists hold the opinion that in the future QDs will apply to flexible display,thinner solar cells and encrypted quantum calculation.As the statement in the Nobel Prize website:“So we have just started exploring the potential of these tiny particles”.We anticipate that the fast development of QDs nanotechniques will facilitate significant improvements of nanomaterials,opening new avenues for long-awaited QDs based myriad optical applications.