Research

Synthesis and Properties of Nanoparticles

The ability to make high-quality nanocrystals with uniform sizes, controlled shapes, and tailored surfaces is central to our research. We synthesize colloidal nanocrystals by injecting molecular precursors into hot coordinating solvents, enabling precise control over nucleation and growth. This allows us to probe fundamental questions of solid-state chemistry: How does nucleation occur? What determines the growth rates of different crystal facets? How do stress and strain evolve at the interfaces of core-shell heterostructures?

We view a nanocrystal as an artificial atom, and extend this concept to design artificial molecules interconnected with nanocrystals of differing size, shape, and composition. To achieve this, we develop modular approaches for chemical transformations, surface derivatization, and post-synthetic ligand exchange. These methods not only expand the accessible library of nanocrystal structures but also allow us to tune key optoelectronic properties such as quantum yield, charge transport, and band structure.

A particular focus of our group is the synthesis of semiconductor nanocrystals, where control over composition, morphology, and crystal phase enables highly tunable electronic and optical properties. These materials hold promise for next-generation applications, including high-efficiency photovoltaics, light-emitting diodes, sensors, and quantum devices.

By combining fundamental insights into nucleation and transformation mechanisms with application-driven design of different semiconductor nanocrystals, our work lays the foundation for a new era of high-performance, eco-friendly, and scientifically rich materials advancing technologies from renewable energy to displays, telecommunications, and even the intersection of nanoscience with art.

Jason J. Calvin, Amanda S. Brewer, A. Paul Alivisatos, Thermodynamics and Modeling of Collective Effects in the Organic Ligand Shell of Colloidal Quantum Dots. Chem. Res. 2025, 58, 271–280.
Joeson Wong*, Mykyta Onizhuk, Jonah Nagura, Arashdeep Singh Thind, Jasleen K. Bindra, Christina Wicker, Gregory D. Grant, Yuxuan Zhang, Jens Niklas, Oleg G. Poluektov, Robert F. Klie, Jiefei Zhang, Giulia Galli, F. Joseph Heremans, David D. Awschalom, and A. Paul Alivisatos*, Coherent Erbium Spin Defects in Colloidal Nanocrystal Hosts. ACS Nano 2024, 18, 19110–19123.
Jakob C. Dahl, Ethan B. Curling, Matthias Loipersberger, Jason J. Calvin, Martin Head-Gordon, Emory M. Chan, and A. Paul Alivisatos*, Precursor Chemistry of Lead Bromide Perovskite Nanocrystals. ACS Nano 2024, 18, 22208–22219.
Jason Calvin, Amanda S. Brewer, and A. Paul Alivisatos*, The role of organic ligand shell structures in colloidal nanocrystal synthesis. Synth. 2022. 1, 127–137.

Advancing electron microscopy to see single atom chemical reactions in liquid

Modern chemistry begins with careful measurement of natural phenomena. We advance the field of chemistry by developing a new analytical technique that enables direct observation of chemical reactions at the atomic level. The analytical technique is based on liquid-cell transmission electron microscopy (TEM), which the Alivisatos group pioneered to see individual nanomaterials suspended in liquid. Through continued efforts, we are able to see structural changes in nanocrystals by chemical reactions, even at the atomic resolution, and in 3D. We are actively pursuing the technology to see single-atom chemical reactions in liquid under broader and realistic environments, in a more routine manner, through the NSF Center for Multimodal Observations for Single Atom Imaging of Chemistry (MOSAIC). By doing so, we will bring unprecedented clarity to the dynamic behavior of individual atoms during chemical processes. These insights hold the potential to transform industries such as energy storage, catalysis, manufacturing, opto-electronics, and beyond.

Selected publications:

Shengsong Yang, Binyu Wu, Chang Liu, Sungsu Kang, and A. Paul Alivisatos*, Chemically Tailorable Dissolution Pathways of Individual Cu₃As Nanocrystals. ACS Nano, 2025, ASAP.
Xingzhi Wang, Chang Yan, Justin C. Ondry, Viraj Bodiwala, Peter Ercius, A. Paul Alivisatos*, An Artificial Intelligence’s Interpretation of Complex High-Resolution in Situ Transmission Electron Microscopy Data. Matter 2024, 7, 175–190.
Michelle F. Crook, Ivan A. Moreno-Hernandez, Justin C. Ondry, Jim Ciston, Karen C. Bustillo, Alfred Vargas, A. Paul Alivisatos*, EELS Studies of Cerium Electrolyte Reveal Substantial Solute Concentration Effects in Graphene Liquid Cells. J. Am. Chem. Soc. 2023, 145, 6648–6657.
Chang Yan, Dana Byrne, Justin C. Ondry, Axel Kahnt, Ivan A. Moreno-Hernandez, Gaurav A. Kamat, Zi-Jie Liu, Christian Laube, Michelle F. Crook, Ye Zhang, Peter Ercius, and A. Paul Alivisatos, A. P. Facet-selective etching trajectories of individual semiconductor nanocrystals. Adv. 2022, 8, abq1700.
Vida Jamali, Cory Hargus, Assaf Ben-Moshe, Amirali Aghazadeh, Hyun Dong Ha, Kranthi K. Mandadapu, and A. Paul Alivisatos*, Anomalous nanoparticle surface diffusion in LCTEM is revealed by deep learning-assisted analysis. PNAS 2021, 118, e2017616118.

Spectroscopy and Structural Studies of Colloidal Nanocrystals.

The way colloidal semiconductor nanocrystals, or quantum dots, interact with light is closely tied to their atomic-scale structure, from crystal symmetry and surface chemistry to the motion of atoms within the lattice. In our lab, we study these structural features and their dynamics using a combination of light-, X-ray-, and electron-based techniques. We then connect structural insights to the optical properties of quantum dots through both steady-state and ultrafast spectroscopies, uncovering how light and matter interact in these nanoscale systems. This approach allows us to reveal the mechanisms behind complex phenomena such as energy up-conversion, coupled electronic–lattice states, and coherent vibrations of nanocrystals. These discoveries not only deepen our fundamental understanding but also guide the rational design of new nanomaterials for advanced optoelectronic and photonic technologies.

Selected publications:

Abdullah S. Abbas, Daniel Chabeda, Daniel Weinberg, David T. Limmer, Eran Rabani, and A. Paul Alivisatos*, Non-monotonic size-dependent exciton radiative lifetime in CsPbBr3 nanocrystals. Commun. 2025, 16, 6401.
Abdullah S. Abbas, Beiye C. Li, Richard D. Schaller, Vitali B. Prakapenka, Stella Chariton, Daqian Bian, Gregory S. Engel, and A. Paul Alivisatos*, Efficient up-conversion in CsPbBr₃ nanocrystals via phonon-driven exciton-polaron formation. Commun. 2025, 16, 5803.
Jakob C. Dahl, Ethan B. Curling, Matthias Loipersberger, Jason J. Calvin, Martin Head-Gordon, Emory M. Chan, and A. Paul Alivisatos*, Precursor Chemistry of Lead Bromide Perovskite Nanocrystals. ACS Nano 2024, 18, 22208–22219.
Chang Yan, Daniel Weinberg, Dipti Jasrasaria, Matthew A. Kolaczkowski, Zi-jie Liu, John P. Philbin, Arunima D. Balan, Yi Liu, Adam M. Schwartzberg, Eran Rabani*, and A. Paul Alivisatos*, Uncovering the role of hole traps in promoting hole transfer from multiexcitonic quantum dots to molecular acceptors. ACS Nano 2021, 15, 2281-2291.

Advancing Quantum Information Science with Scalable Materials

We aim to explore colloidal nanocrystals as next-generation hosts for quantum coherent, optically addressable spin defects, seeking to extend the capabilities of quantum information science. By investigating the use of Er³⁺ spin defects in colloidal ceria nanocrystals, we have demonstrated microsecond-long spin coherence times, on par with or exceeding those of traditional quantum materials such as diamond and superconducting qubits. This groundbreaking work not only highlights the exceptional performance of these nanocrystals but also offers exciting possibilities for integrating quantum technologies with existing telecommunications infrastructure, thanks to the near-infrared optical transitions of Er³⁺. Our research aims to leverage the scalability and versatility of colloidal nanocrystals to drive advancements in quantum computing and communication, pushing the boundaries of what is possible in the field.

Selected publications:

Joeson Wong*, Mykyta Onizhuk, Jonah Nagura, Arashdeep S. Thind, Jasleen K. Bindra, Christina Wicker, Gregory D. Grant, Yuxuan Zhang, Jens Niklas, Oleg G. Poluektov, Robert F. Klie, Jiefei Zhang, Giulia Galli, F. Joseph Heremans, David D. Awschalom, A. Paul Alivisatos*, Coherent Erbium Spin Defects in Colloidal Nanocrystal Hosts. ACS Nano 2024, 18, 19110-19123.

Art with Nanoparticles

Craftsmen were arguably the first nanoscientists. Artifacts from as early as the Bronze Age reveal that artisans harnessed nanoscale phenomena to produce a variety of effects: lustre in early Islamic ceramics, enhanced strength in 9th-century Syrian swords, and rich colors in ancient Roman, Egyptian, Chinese, and medieval European glass. Historians of science tell us that early craftsmen’s practices-gathering information through direct observation, measuring materials to promote reproducible results, and changing one variable at a time-did much to shape the methodology of science. Walk into a contemporary nanoscience lab, and you will find scientists using techniques that derive from ones developed by artists-for example, nanolithography and Lagmuir-Blodgett film-casting.

Thus, it is natural that an interdisciplinary lab such as ours would include an artist. Our artist-in-residence, Kate Nichols, was initially drawn to using nanomaterials because of her interest in structurally colored Morpho butterflies. (Morpho butterflies appear as brilliant blue despite their lack of blue pigmentation. Their blue color is structural rather than chemical, deriving from nanoscale features within their wings.) Once in our lab, Kate was inspired by medieval artisans’ use of plasmonic nanoparticles in stained glass windows. She synthesizes similar plasmonic nanoparticles and uses them to create macroscale art whose structural colors arise from surface plasmon resonance. In her painting, photography, and writing, Kate continues to explore natural photonic structures. Her work can be seen at The Leonardo, a museum of art and science in Salt Lake City, on her website, and at TED.

In a recent collaboration with artist Amanda Williams, we revived a century-old pigment recipe patented by George Washington Carver. Carver’s 1927 patent described producing a striking blue pigment from Alabama red clay, but the method relied on long, hazardous acid treatments. Our team adapted the chemistry using modern equipment, including centrifuges, safer acids, and controlled reaction conditions, to achieve reproducible pigment production within hours. Structural analysis confirmed the pigment to be Prussian blue, historically one of the first synthetic colors. The resulting “Carver blue” was scaled up and transformed into paints, which Williams used in major art installations, including at the Prospect.6 triennial in New Orleans and in her New York solo exhibition Run Together and Look Ugly After the First Rain. The project highlights the enduring dialogue between chemistry and art, linking nanoscale materials research to broader cultural narratives and celebrating Black ingenuity and innovation.