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"Energy Efficient Dissociation of Excitons to Free Charges", Maxim Tabachnyk, Samuel L. Smith, Leah R. Weiss, Aditya Sadhanala, Alex W. Chin, Richard H. Friend, Akshay Rao.  arXiv:1704.03780



"Order Enables Efficient Electron-hole Separation at an Organic Heterojunction with a Small Energy Loss", S. Matthew Menke, Alexandre Cheminal, Patrick Conaghan, Niva A. Ran, Neil C. Greehnam, Guillermo C. Bazan, Thuc-Quyen Nguyen, Akshay Rao, Richard H. Friend, Nature Communications 9, Article number: 277, (2018), DOI:10.1038/s41467-017-02457-5, Full Text here.


“Singlet Fission and Triplet Transfer to PbS Quantum Dots in TIPS-Tetracene Carboxylic Acid Ligands”, Nathaniel J. L. K. Davis, Jesse R. Allardice, James Xiao, Anthony J. Petty, Neil C. Greenham, John E. Anthony, and Akshay Rao, The Journal of Physical Chemistry Letters9, pp 1454–1460, DOI: 10.1021/acs.jpclett.8b00099, (2018), Full Text.



"Elucidation of Excitation Energy Dependent Correlated Triplet Pair Formation Pathways in an Endothermic Singlet Fission System", Arya Thampi, Hannah L. Stern, Alexandre Cheminal, Murad J. Y. Tayebjee, Anthony J. Petty II, John E. Anthony and Akshay Rao,  Journal of the American Chemical Society, DOI: 10.1021/jacs.7b06274, Full Text here


"Real-Time Observation of Exciton-Phonon Coupling Dynamics in Self-Assembled Hybrid Perovskite Quantum Wells", Limeng Ni, Uyen Huynh, Alexandre Cheminal, Tudor H. Thomas, Ravichandran Shivanna, Ture F. Hinrichsen, Shahab Ahmad, Aditya Sadhanala and Akshay Rao, ACS NANO, DOI: 10.1021/acsnano.7b03984, Full Text here.


"Harnessing singlet exciton fission to break the Shockley–Queisser limit", Akshay Rao & Richard H Friend, Nature Reviews Materials, 2, Article number: 17063, DOI: 10.1038/natrevmats.2017.63, (2017), Full text here, Open access here


"Ultrafast Triplet Pair Formation and Subsequent Thermally Activated Dissociation Control Efficient Endothermic Singlet Exciton Fission", Hannah L Stern, Alexandre Cheminal, Shane R Yost, Katharina Broch, Sam L Bayliss, Kai Chen, Maxim Tabachnyk, Karl Thorley, Neil Greenham, Justin Hodgkiss, John Anthony, Martin Head-Gordon, Andrew J Musser, Akshay Rao, Richard H Friend.  Nature Chemistry, DOI: 10.1038/nchem.2856, (2017) , Full text here, Open access here


“Visualising Excitations at Buried Heterojunctions in Organic Semiconductor Blends”, Andreas C. Jakowetz, Marcus L. Böhm, Aditya Sadhanala, Sven Huettner, Akshay Rao and Richard H. Friend, Nature Materials, (2017), doi:10.1038/nmat4865. Full Text.


"Ultrafast Long-Range Charge Separation in Nonfullerene Organic Solar Cells", Yasunari Tamai, Yeli Fan, Vincent O. Kim, Kostiantyn Ziabrev, Akshay Rao, Stephen Barlow, Seth R. Marder, Richard H. Friend and S. Matthew Menke, ACS Nano, DOI: 10.1021/acsnano.7b06575, Full Text here


"On the energetics of bound charge-transfer states in organic photovoltaics", Jiangbin Zhang, Andreas Jakowetz, Guangru Li, Dawei Di, Stephen Matthew Matthew Menke, Akshay Rao, Richard Friend, Artem A Bakulin, J. Mater. Chem. A, 2017, Advance Article, Full Text



"Real-Time Observation of Multiexcitonic States and Ultrafast Singlet Fission Using Coherent 2D Electronic Spectroscopy", Artem A. Bakulin, Sarah E. Morgan, Tom B. Kehoe, Mark W.B Wilson, Alex Chin, Donatas Zigmantas, Dassia Egorova, Akshay Rao. Nature Chemistry,  8, 16, (2016), Full Text.

 Nature Image - Variations - 02.png

“Observation of Strongly Exchange-Coupled Triplet Pairs in an Organic Semiconductor”, Leah R. Weiss, Sam L. Bayliss, Felix Kraffert, Karl J. Thorley, John E. Anthony, Robert Bittl, Richard Friend, Akshay Rao, Neil C. Greenham, and Jan Behrends. Nature Physics, (2016).  Full Text.


“What Controls the Rate of Ultrafast Charge Transfer and Charge Separation Efficiency in Organic Photovoltaic Blends”, Andreas C Jakowetz, Marcus L Böhm, Jiangbin Zhang, Aditya Sadhanala, Sven Huettner, Artem A Bakulin, Akshay Rao, and Richard H Friend. Journal of the American Chemical Society, (2016).  Full Text.


“Sub-10 Femtosecond Time-Resolved Vibronic Microscopy”, Christoph Schnedermann, Jong Min Lim, Torsten Wende, Alex Soares Duarte, Limeng Ni, Qifei Gu, Aditya Sadhanala, Akshay Rao, and Philipp Kukura, The Journal of Physical Chemistry Letters, DOI: 10.1021/acs.jpclett.6b02387, (2016), Full Text.


“Synthesis and Optical Properties of Lead-Free Cesium Tin Halide Perovskite Nanocrystals”, Tom C Jellicoe, Johannes M Richter, Hugh FJ Glass, Maxim Tabachnyk, Ryan Brady, Siân E Dutton, Akshay Rao, Richard H Friend, Dan Credgington, Neil C Greenham, and Marcus L Böhm. Journal of the American Chemical Society, 138, 9, (2016). Full Text.


“Spin signatures of exchange-coupled triplet pairs formed by singlet fission”, Sam L Bayliss, Leah R Weiss, Akshay Rao, Richard H Friend, Alexei D Chepelianskii, and Neil C Greenham. Physical Review B, 94, 4, (2016). Full Text.


“A Complete Quantitative Analysis of Spatio‐Temporal Dynamics of Excitons in Functional Organic Light‐Emitting Diodes”, Amrita Dey, Akshay Rao, Dinesh Kabra. Advanced Optical Materials, DOI: 10.1002/adom.201600678. Full Text.


“Charge Generation and Electron-Trapping Dynamics in Hybrid Nanocrystal-Polymer Solar Cells”, Frederik S. F. Morgenstern, Marcus L. Böhm, René J. P. Kist, Aditya Sadhanala, Simon Gélinas, Akshay Rao, and Neil C. Greenham. J. Phys. Chem. C, DOI: 10.1021/acs.jpcc.6b07591. Full Text.



“Evidence for Conical Intersection Dynamics Mediating Ultrafast Singlet Exciton Fission”, Andrew J. Musser, Matz Liebel, Christoph Schnedermann, Torsten Wende, Tom B. Kehoe, Akshay Rao, Philipp Kukura. Nature Physics, 11, 352–357 (2015). Full Text.


“Electroluminescence from Organometallic Lead Halide Perovskite-Conjugated Polymer Diodes”, Aditya Sadhanala, Abhishek Kumar, Sandeep Pathak, Akshay Rao, Ullrich Steiner, Neil C. Greenham, Henry J. Snaith and Richard H. Friend. Advanced Electronic Materials1, 3, (2015). Full Text.



Triplet Transfer

“Resonant Energy Transfer of Triplet Excitons from Pentacene to PbSe   Nanocrystals”, Maxim Tabachnyk, Bruno Ehrler, Simon Gélinas, Marcus L. Böhm, Brian J. Walker, Kevin P. Musselman, Neil C. Greenham, Richard H. Friend and Akshay Rao. Nature Materials, 13, 1033–1038 (2014). Full Text


Coherent Charge Separation
 “Ultrafast Long-Range Charge Separation in Organic Semiconductor Photovoltaic Diodes”, Simon Gélinas­, Akshay Rao, Abhishek Kumar, Samuel L. Smith, Alex W. Chin, Jenny Clark, Tom S. van der Poll, Guillermo C. Bazan, Richard H. Friend, Science, 343, 6170, 512-516, (2014).


JACS 2014
“Unequal Partnership: Asymmetric Roles of Polymeric Donor and Fullerene Acceptor in Generating Free Charge” Brett M. Savoie, Akshay Rao, Artem A. Bakulin, Simon Gelinas, Bijan Movaghar, Richard H. Friend, Tobin J. Marks, Mark A. Ratner. Journal of the American Chemical Society, 136 (7), 2876–2884, (2014) .



Singlet Fission Nature Chem 2014

“A Transferable Model For Singlet Fission Kinetics”, Shane R. Yost, Jiye Lee, Mark W. B. Wilson, David P. McMahon, Rebecca R. Parkhurst, Nicholas J. Thompson, Akshay Rao, Kerr K. F. Johnson, Matthew Y. Sfeir, Timothy M. Swager, Richard H. Friend, Marc A. Baldo and Troy Van Voorhis. Nature Chemistry, 6, 492–497 (2014).


“Ultrafast Charge and Energy Transfer Dynamics in Conjugated Polymer: Cadmium Selenide Nanoparticle Blends”, Frederik S.F. Morgenstern, Akshay Rao, Marcus L. Boehm, René J.P. Kist, Yana Vaynzof and Neil C. Greenham. ACS NANO, 8 (2), 1647–1654, (2014)


“Quantitative Bimolecular Recombination in Organic Photovoltaics through Triplet Exciton Formation”, Philip C.Y. Chow, Simon Gélinas, Akshay Rao, Richard H. Friend, Journal of the American Chemical Society, 136 (9), 3424–3429, (2014).


“How Disorder Controls the Kinetics of Triplet Charge Recombination in Semiconducting Organic Polymer Photovoltaics”, Eric R. Bittner, Vladimir Lankevic, Simon Gélinas, Akshay Rao, David A. Ginger and Richard H. Friend, Phys. Chem. Chem. Phys., 16, 20321, (2014),


"First Principles Calculations of Charge Transfer Excitations in Polymer–Fullerene Complexes: Influence of Excess Energy", Dorota Niedzialek, Ivan Duchemin, Thiago Branquinho de Queiroz, Silvio Osella, Akshay Rao, Richard Friend, Xavier Blase, Stephan Kümmel, David Beljonne, Advanced Functional Materials,  25, 13, 1972–1984, (2014) doi: 10.1002/adfm.201402682


“Trap-Induced Losses in Hybrid Photovoltaics”, Feng Gao, Zhe Li, Jianpu Wang, Akshay Rao, Ian A. Howard, Agnese Abrusci, Sylvain Massip, Christopher R. McNeill and Neil C. Greenham. ACS NANO, 8 (4), 3213-3221, (2014).


“Bimolecular Recombination in Organic Photovoltaics”, Girish Lakhwani, Akshay Rao, Richard H Friend, Annual Review of Physical Chemistry, 65, (2014).


“Interface limited charge extraction and recombination in organic photovoltaics”, Abhishek Kumar, Girish Lakhwani, Einat Elmalem, Wilhelm T. S. Huck, Akshay Rao, Neil C. Greenham and Richard H. Friend, Energy & Environmental Science, 7, 2227-2231, (2014)




Nature OPV Recombination

“The Role of Spin for Kinetic Control of Recombination in Organic Photovoltaics”, Akshay Rao, Philip C.Y. Chow, Simon Gélinas, Cody W. Schlenker, Chang-Zhi Li, Hin-Lap Yip, Alex K-Y. Jen, David S. Ginger, Richard H. Friend, Nature, 500 (7463), 435-439, (2013).


“Temperature-Independent Singlet Exciton Fission in Tetracene”, Mark W. B. Wilson, Akshay Rao, Kerr Johnson, Simon Gélinas, Riccardo di Pietro, Jenny Clark, Richard H. Friend, Journal of the American Chemical Society, 135 (44), 16680–16688, (2013).


“Singlet Exciton Fission in Polycrystalline Pentacene: From Photophysics toward Devices”, Mark W. B. Wilson, Akshay Rao, Bruno Ehrler, Richard H Friend, Accounts of Chemical Research, 46 (6), 1330–1338, (2013).


“Triplet Dynamics in Pentacene Crystals: Applications to Fission-Sensitized Photovoltaics”, Andrey D. Poletayev, Jenny Clark, Mark W. B. Wilson, Akshay Rao, Yoshitaka Makino, Shu Hotta, Richard H. Friend, Advanced Materials, 26, 919–924, (2013).




Delocalised States - Science 2012

 “The Role of Driving Energy and Delocalised States for Charge Separation in Organic Semiconductors”, Artem A. Bakulin, Akshay Rao, Vlad G. Pavelyev, Dorota Niedzialek, Jérôme Cornil, David Beljonne, Paul H.M. van Loosdrecht, Maxim S. Pshenichnikov, Richard H. Friend, Science, 335, 6074, 1340-1344, (2012).


“Charge-Transfer State Dynamics Following Hole and Electron Transfer in Organic Photovoltaic Devices” Artem A Bakulin, Stoichko D Dimitrov, Akshay Rao, Philip CY Chow, Christian B Nielsen, Bob Camille Schroeder, Iain McCulloch, Huib J Bakker, James R Durrant, Richard H Friend, The Journal of Physical Chemistry Letters, 4 (1), 209–215, (2012).


“Singlet Exciton Fission-Sensitized Infrared Quantum Dot Solar Cells”, Bruno Ehrler, Mark W. B. Wilson, Akshay Rao, Richard H. Friend and Neil C. Greenham, Nano Letters, 12 (2), 1053–1057 (2012).


“Exciton-charge annihilation in organic semiconductor films”, Justin M. Hodgkiss, Sebastian Albert-Seifried, Akshay Rao, Alex Barker, Andrew R. Campbell, R. Alex Marsh, and Richard H. Friend, Advanced Functional Materials, 22 (8), 1567–1577, (2012).

“Excitons and charges at organic semiconductor heterojunctions”, Richard H Friend, Matthew Phillips, Akshay Rao, Mark W.B. Wilson, Zhe Li and Christopher R McNeill, Faraday Discussions, 155, 339-348, (2012).



“Photophysics of Pentacene Thin Films: The Role of Exciton Fission and Heating Effects”, Akshay Rao,Mark W. B. Wilson,Sebastian Albert-Seifried, Riccardo Di Pietro and Richard H. Friend, Physical Review B, 84, 195411, (2011)


“Ultrafast Dynamics of Exciton Fission in Polycrystalline Pentacene”, Mark W.B. Wilson, Akshay Rao, J. Clark, R. S. S. Kumar, D. Brida, G. Cerullo, and R. H. Friend, Journal of the American Chemical Society, 133 (31), 11830–11833, (2011).


“Time-Evolution of Poly(3-Hexylthiophene) as an Energy Relay Dye in Dye-Sensitized Solar Cells”, Nicola Humphry‐Baker, Kristina Driscoll, Akshay Rao, Tomas Torres, Henry Snaith, Richard Friend, Nano Letters (2011).


“Studies on All-Polymer Photovoltaics Containing a New High-Electron-Mobility Polymer”, Jennifer R. Moore, Sebastian Albert-Seifried, Akshay Rao, Sylvain Massip, Benjamin Watts, David J. Morgan, Richard H. Friend, Christopher R. McNeill and Henning Sirringhaus, Advanced Energy Materials, 1, 230–240, (2011).



Singlet Fission and Charge Generation

“Exciton Fission and Charge Generation via Triplet Excitons in Pentacene/C60 Bilayers”, Akshay Rao, Mark W.B. Wilson, Justin M. Hodgkiss, Sebastian Albert-Seifried, Heinz Bassler and Richard H. Friend. Journal of the American Chemical Society, 132 (36), 12698–12703, (2010).


“Subnanosecond Geminate Charge Recombination in Polymer-Polymer Photovoltaic Devices”, Justin M. Hodgkiss, Andrew R. Campbell, R. Alex Marsh, Akshay Rao, Sebastian Albert-Seifried, and Richard H. Friend, Physical Review Letters, 104, 177701, (2010).


“Polymeric spin-valves at room temperature”, Nicola A Morley, D Dhandapani, A Rao, H Al Qahtani, MRJ Gibbs, M Grell, D Eastwood and BK Tanner, Synthetic Metals, 161, 7–8, 558–562, (2010).



“Efficient ZnO Nanowire Solid-State Dye-Sensitized Solar Cells Using Organic Dyes and Core−shell Nanostructures”, Natalie O. V. Plank, Ian Howard, Akshay Rao J. Phys. Chem. C113 (43), 18515–18522, (2009).


“Effect of polymer processing on spin magnetoresistance in organic structures”, D. Dhandapani, A. Rao, N. A. Morley, A. Das, M. Grell, and M. R. J. Gibbs. J. Appl. Phys. 105, 07C702, (2009).



“Comparison of Room Temperature Polymeric Spin-Valves With Different Organic Components”, D. Dhandapani, N. A. Morley, A. Rao, A. Das, M. Grell, and M. R. J. Gibbs. IEEE Transactions On Magnetics, Vol. 44, No. 11, (2008).


“Room temperature organic spintronics”, N. A. Morley, A. Rao, D. Dhandapani, M. R. J. Gibbs, M. Grell, and T. Richardson. J. Appl. Phys. 103, 07F306 (2008).

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2 Postdoc Positions Open

Mar 02, 2018

Two postdoc positions, one in ultrafast spectroscopy and the other to work on Colloidal Nanocrystals are available. Please see the Join the Group tab for details

Paper accepted to Nature Communications

Nov 15, 2017

Matt and Alex's paper on the role of order in the charge separation process in OPVs is accepted to Nature Communications.

Paper accepted to ASC Nano

Oct 24, 2017

Limeng's paper on exciton-phonon coupling in hybrid perovskite quantum wells is accepted to ACS NANO.

Paper published in Nature Reviews

Oct 05, 2017

Our review of Singlet Fission is published in Nature Reviews Materials

ERC Starter Grant

Sep 18, 2017

Our project SOLARX is funded by the ERC.

Paper published in Nature Chemistry

Sep 11, 2017

Hannah and Alex's paper on ultrafast 'endothermic' singlet fission is published in Nature Chemistry.

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