Directing Electrons with Light



Exciting additions to the group! Will Carson from Miami University joins as a Columbia MRSEC REU student; Jack Tulyag and Inki Lee, incoming Columbia graduate students, join as summer GRAs.


New article out in ACS Energy Letters! Using stroboSCAT to image charge transport in two lead-free double halide perovskites, we find that carrier diffusion lengths exceed 1 micron despite shallow trap-limited transport. These diffusion lengths combined with good absorption properties suggest that halide double perovskites are viable candidates to rival the archetypal lead halide perovskites for photovoltaic applications.


Eileen Moudou, an undergraduate student at Columbia College, joins the group. Welcome!

Read all news here.


The efficient transport and interconversion of energy between photons, electrons, ions and heat underpins life on earth. In modern technologies ranging from solar panels to computers, batteries and health sensors, energy moves slowly, randomly and often inefficiently towards target conversion sites. We aim to direct energy flow in emerging materials in ways that are targeted and efficient, moving beyond random motion to unleash new paradigms for extracting more energy from solar panels, storing more energy in batteries, speeding up information transport and processing, and exploiting correlated electronic systems for new applications.


We use light as a powerful stimulus to initiate, image and control electronic behavior in emerging materials on extreme spatiotemporal scales. Questions we explore include:

  • How do we image individual electrons moving and interacting with their surroundings in material lattices?

  • How do we control the direction and speed at which energy packets move towards functional targets?

  • How do we unlock exotic emergent phenomena and exploit them in modern devices?

The ongoing explosion of discoveries in quantum, meta- and nanomaterials provides the perfect platform for us to answer these questions now.


Super-resolution imaging

of electronic transport and material energy landscapes

Optical control of nuclear-electronic coupling and energy flow on material mesoscales


Optical manipulation of strongly correlated electronic behavior with confined light

In the process of answering these questions, we invent new tools capable of non-invasively imaging events happening over femtoseconds to hours at the single-nanometer scale. These tools are often relevant to a broad range of scientific disciplines: think taking movies of self-assembling biological or material building blocks, of neurons emitting action potentials, and of non-dissipative electronic transport in superconductors.

In addition to gaining a deep fundamental understanding of light-matter interactions, students and postdocs in the group acquire experience in nonlinear optics, super-resolution microscopy, ultrafast visible, IR and terahertz spectroscopy, and materials design and characterization. We collaborate broadly with both theoretical and experimental research groups at Columbia and beyond.


intro picture_Shan-Wen_edited.jpg


Graduate Student




Graduate Student




Assistant Professor
and Principal Investigator



Postdoctoral scholar, 2016-2019

Ginsberg group, University of California, Berkeley

Doctoral Prize Fellow, 2015

​PhD Physical Chemistry, 2010-2014

Weinstein group, University of Sheffield​

BSc Chemistry, 2015-2019

National Taiwan University

BA Chemistry and Global Health, 2015-2019

Washington University in St. Louis



Graduate Student




Undergraduate Student




Graduate Student


BSc Chemistry, 2014-2019

Wuhan University

​Visiting researcher, North Carolina
State University

BA Chemistry and Mathematics

Columbia University

BS Chemistry & Physics, 2016-2020

University of California, Los Angeles



Graduate Student


BS Chemistry, 2016-2020

University of Texas at Austin

Read more about the team here.

We continue to look for motivated students and postdocs interested in spectroscopy, microscopy and materials science to join the group. Postdoc candidates have a strong background in chemical physics or physical chemistry and experience with one or a combination of the following: ultrafast spectroscopy, super-resolution microscopy, quantum materials, nonlinear optics. Contact Milan for more information.


Delor M, Slavney A, Wolf N, Filip M, Neaton J, Karunadasa H, Ginsberg N (2020).

Carrier diffusion lengths exceeding 1 μm despite trap-limited transport in halide double perovskites

ACS Energy Letters, vol. 5, pp. 1337-1345.

Delor M, Weaver H, Yu Q, Ginsberg N (2020).

Imaging material functionality through 3D nanoscale tracking of energy flow

Nature Materials, vol. 19, pp. 56-62.


Delor M*, Dai J*, Roberts T*, Rogers J*, Hamed S, Neaton J, Geissler P, Francis M, Ginsberg N (2018).

Exploiting chromophore–protein interactions through linker engineering to tune photoinduced dynamics in a biomimetic light-harvesting platform

Journal of the American Chemical Society, vol. 140, pp. 6278–6287.


Delor M, Archer S, Keane T, Meijer A, Sazanovich I, Greetham G, Towrie M, Weinstein J (2017).

Directing the path of light-induced electron transfer at a molecular fork using vibrational excitation

Nature Chemistry, vol. 9, pp. 1099-1104.


Delor M, Keane T, Scattergood P, Sazanovich I, Towrie M, Meijer A, Weinstein J (2015).

On the mechanism of vibrational control of light-induced charge transfer in donor–bridge–acceptor assemblies

Nature Chemistry, vol.17, pp. 689-695.


Delor M, Sazanovich I, Towrie M, Weinstein J (2015).

Probing and exploiting the interplay between nuclear and electronic motion in charge transfer processes

Accounts of Chemical Research, vol. 48, pp. 1131-1139.


Delor M, Scattergood P, Sazanovich I, Parker A, Greetham G, Meijer A, Towrie M, Weinstein J (2014).

Toward control of electron transfer in donor-acceptor molecules by bond-specific infrared excitation

Science, vol. 346, pp. 1492-1495.



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