Chan Research Group @ Univ. of Kansas

Our research focuses on understanding the fundamental electronic processes, such as exciton transport and charge transfer, in molecular solids, conjugated polymers, organic-inorganic hybrid systems and 2-D layered crystals. These materials can be potentially used in next generation devices for applications ranging from light harvesting (e.g. solar energy, photocatalysis) to flexible electronics. However, the lack of fundamental understandings in the electron dynamics of these materials can hinder future applications. Using novel experimental techniques such as time-resolved two photon photoemission spectroscopy, time-resolved electrical measurements and optical spectroscopy, we probe the dynamics of photoexcited electrons and molecules in an ultrafast timescale (10-14 – 10-9 s). A better understanding of these processes will help us to design cost-effective ways to produce energy.

Research sponsored by:

Recent Research Projects

Full publication list can be found at:


1. Coherent Exciton Transport and Charge Transfer in Organic Semiconductors


Selected Publication:

Kattle, B., Qin, L., Kafle, T. R., & Chan, W. -L.

Graphene Field-Effect Transistor as a High-Throughput Platform to Probe Charge Separation at Donor-Acceptor Interfaces

J. Phys. Chem. Lett. 9, 1633-1641 (2018)


Wang, T., Kafle, T., Kattel, B., & Chan, W.-L.

A Multi-Dimensional View of Charge Transfer Excitons at Organic

Donor-Acceptor Interfaces

J. Am. Chem. Soc., 139, 4098-4106 (2017)



Wang, T., Kafle, T., Kattel, B., & Chan, W.-L.,

Observation of an Ultrafast Exciton Hopping Channel in Organic Semiconducting Crystals

J. Phys. Chem. C, 120, 7491-7499 (2016)


Wang, T., & Chan, W. L.,

Dynamical Localization Limiting the Coherent Transport Range of Excitons in Organic Crystal.

J. Phys. Chem. Lett., 5, 1812-1818 (2014)

2. Hybrid organic-2D van der Waals interfaces


Selected Publication:

Kafle, T. R., Kattel, B., Yao, P., Zereshki, P., Zhao, H., & Chan, W. -L.

Effect of the Interfacial Energy Landscape on Photo-induced Charge

Generation at the ZnPc-MoS2 Interface

J. Am. Chem. Soc., 141, 11328-11336 (2019) [Press Release]


Kafle, T. R., Kattel, B., Lane, S., Wang, T., Zhao, H., & Chan, W. -L.

Charge Transfer Exciton and Spin Flipping at Organic-Transition Metal

Dichalcogenide Interface

ACS Nano, 11, 10184-10192 (2017)


Biancardi, A., Caraiani, C., Chan, W.-L., & Caricato, M.

How Number of Layers and Relative Position Modulate the Interlayer Electron Transfer in π-Staked 2D Materials

J. Phys. Chem. Lett., 8, 1365-1370 (2017)


Wang, T., Liu, Q., Caraiani, C., Zhang, Y., Wu, J., & Chan, W.-L.

Effect of Interlayer Coupling on Ultrafast Charge Transfer from Semiconducting Molecules to Mono- and Bilayer Graphene

Phys. Rev. Appl. 4, 014016 (2015)


3. Hybrid-organometallic perovskite, nano-materials optoelectronic devices


Selected Publication:

Qin, L., Wu, L., Kattel, B., Li, C., Zhang, Y., Hou, Y., Wu, J., & Chan, W. –L.

Using Bulk-Heterojunction and Selective Electron Trapping to Enhance

the Responsivity of Perovskite-Graphene Photodetector

Adv. Funct. Mater., 27, 1704173 (2017).





Gong, M., Liu, Q., Cook, B., Kattel, B., Wang, T., Chan, W.-L., Ewing, D., Casper, M., Stramel, A., & Wu, J.

All-printable ZnO quantum dots/Graphene van der Waals heterostructures for ultrasensitive detection of ultraviolet light

ACS Nano, 11, 4114-4123 (2017).


PI:   Wai-Lun Chan


Graduate Students:

Fatimah Rudayni

Kushal Rijal

Ghadah Alkhalifah

Neno Fuller

Elizabeth Udeh

Fatima Lariz


Undergraduate Students:

Madeline Dopp


Previous Members:

Graduate Students:

Shanika Wanigasekara (at Intel)

Bhupal Kattel (at Intel)

Tika Kafle (postdoc at University of Colorado Boulder)



Ti Wang (researcher at Wuhan University)


Visiting PhD student:

Liang Qin (lecturer at Beijing Jiaotong University)


Undergraduate student:

Jack Water

James Allen

Aaron Gehrke (graduate student at University of Washington)

Jonathan Bush

Dalton Jones

Claudiu Caraiani (graduate student at University of Bucharest)

Will Burg (graduate student at Univ. of Texas, Austin)

Cole Lindsey (graduate student at KU)

Published Manuscript:


Deformable Molecular Crystal on 2D Crystal: A New Way to Build Nanoscale Periodic Trapping Sites for Interlayer Excitons

Kushal Rijal, Stephanie Amos, Pavel Valencia-Acuna, Fatimah Rudayni, Neno Fuller, Hui Zhao, Hartwin Peelaers, Wai-Lun Chan


ACS Nano 17, 7775-7786 (2023)








Endothermic Charge Separation Occurs Spontaneously in Non-Fullerene Acceptor/Polymer Bulk Heterojunction

Kushal Rijal, Neno Fuller, Fatimah Rudayni, Nan Zhang, Xiaobing Zuo, Cindy L. Berrie, Hin-Lap Yip, Wai-Lun Chan


submitted to Adv. Mater. (2024)