Optoelectronic Materials and Device Spectroscopy Group (StranksLab)

Our research focuses on the optical and electronic properties of emerging semiconductors for low-cost, transformative electronics applications including light-harvesting (e.g. photovoltaic) and light-emission (eg LED) devices. We use optical spectroscopy to understand material and device photophysics on a range of length and time scales, and relate these characteristics directly to local chemical, structural and morphological properties through multimodal measurements. This provides a unique platform to discover new semiconducting materials, unveil power loss mechanisms in devices, guide innovative device designs, and push device performance to the limits. Our developed devices and in-situ and in-operando imaging approaches are applicable to a range of fields including energy materials, medical imaging and biological systems. We also have a strong emphasis in the group on making our work accessible to the public through a number of outreach and media activities, and on equality, diversity and inclusion efforts.

HIGHLIGHTED RECENT PUBLICATIONS:

• Macpherson, S.; Doherty, T. A. S.; Winchester, A. J.; Kosar, S.; Johnstone, D. N.; Chiang, Y.-H.; Galkowski, K.; Anaya, M.; Frohna, K.; Iqbal, A. N.; Nagane, S.; Roose, B.; Andaji-Garmaroudi, Z.; Orr, K. W. P.; Parker, J. E.; Midgley, P. A.; *Dani, K. M.; *Stranks, S. D. Local nanoscale phase impurities are degradation sites in halide perovskites Nature 2022, In Press, DOI: 10.1038/s41586-022-04872-1
• Frohna, K.; *Anaya, M.; Macpherson, S.; Sung, J.; Doherty, T. A. S.; Chiang, Y.-H.; Winchester, A. J.; Orr, K. W. P.; Parker, J. E.; Quinn, P. D.; Dani, K. M.; Rao, A.; *Stranks, S. D. Nanoscale chemical heterogeneity dominates the optoelectronic response of alloyed perovskite solar cells Nat. Nanotech. 2022, DOI: 10.1038/s41565-021-01019-7
• Doherty, T. A. S.; Nagane, S.; Kubicki, D. J.; Jung, Y.-K.; Johnstone, D. N. ; Iqbal, A. N.; Guo, D.; Frohna, K.; Danaie, M.; Tennyson, E. M.; Macpherson, S.; Abfalterer, A.; Anaya, M.; Chiang, Y.-H.; Crout, P.; Ruggeri, F. S.; Collins, S.; Grey, C. P.; Walsh, A.; Midgley, P. A.; *Stranks, S. D. Stabilized tilted-octahedra halide perovskites inhibit local formation of performance-limiting phases Science 2021, 374(6575), 1598-1605
• Liu, D.; Luo, D.; Iqbal, A.N.; Orr, K.W.P.; Doherty, T.A.S.; Lu, Z.; *Stranks, S.D.; *Zhang, W. Strain analysis and engineering in halide perovskite photovoltaics Nature Materials 2021, DOI: 10.1038/s41563-021-01097-x
• Kubicki, D.J.; *Stranks, S.D.; *Grey, C.P.; *Emsley, L. NMR spectroscopy probes microstructure, dynamics and doping of metal halide perovskites Nature Reviews Chemistry 2021, DOI: 10.1038/s41570-021-00309-x
• Bowman, A.R.; Anaya, M; Greenham N.C.; *Stranks, S.D. Quantifying Photon Recycling in Solar Cells and Light-Emitting Diodes: Absorption and Emission Are Always Key Phys. Rev. Lett. 2020, DOI:10.1103/PhysRevLett.125.067401
• Doherty, T. A. S.; Winchester, A, J.; Macpherson, S. M.; Johnstone, D. N.; Pareek, V.; Tennyson E. M.,; Kosar, S.; Kosasih, F. U.; Anaya, M.; Abdi-Jalebi, M.; Andaji-Garmaroudi, Z.; Wong, E. L.; Madéo, J.; Chiang, Y.-H.; Park, J.-S.; Jung, Y.-K.; Petoukhoff, E. C.; Divitini, G.; Man, M. K. L.; Ducati, C.; Walsh, A.; Midgley, P. A.; *Dani, K.; *Stranks, S. D. Visualising Performance-Limiting Nanoscale Trap Clusters at Grain Junctions in Halide Perovskites Nature 2020, DOI: 10.1038/s41586-020-2184-1
• Kubicki, D. J.; Prochowicz, D.; Salager, E.; Rakhmatullin, A.; *Grey, C. P.; *Emsley, L.; *Stranks, S. D. Local Structure and Dynamics in Methylammonium, Formamidinium and Cesium Tin(II) Mixed-Halide Perovskites from 119Sn Solid-State NMR J. Am. Chem. Soc. 2020, DOI: 10.1021/jacs.0c00647
• †Feldmann, S.; †Macpherson, S.; Senanayak, S. P.; Abdi-Jalebi, M.; Rivett, J. P. H.; Nan, G.; Tainter, G. D.; Doherty, T. A. S.; Frohna, K.; Ringe, E.; Friend, R. H.; Sirringhaus, H.; Saliba, M.; Beljonne, D.; *Stranks, S. D.; *Deschler, F. Photo-doping through local charge carrier accumulation in alloyed hybrid perovskites for highly efficient luminescence, Nature Photonics, 2020, 14, 123-128
• Anaya, M.; Rand, B. P.; Holmes, R. J.; Credgington, D.; Bolink, H. J.; Friend, R. H.; Wang, J.; Greenham, N. C.; *Stranks, S. D. Best practices for measuring emerging light-emitting diode technologies, Nature Photonics, 2019, 13, 818–821
• Tennyson, E. M.; Doherty, T. A. S.; Stranks, S. D. Heterogeneity at multiple length scales in halide perovskite semiconductors, Nature Reviews Materials, 2019, 4, 573-587
• Abdi-Jalebi, M.; Andaji-Garmaroudi, Z.; Cacovich, S.; Stavrakas, C.; Philippe, B.; Richter, J. M.; Alsari, M.; Booker, E. P.; Hutter, E. M.; Pearson, A. J., Lilliu, S.; Savenije, T. J.; Rensmo, H.; Divitini, G.; Ducati, C.; Friend, R. H.; *Stranks., S. D. Maximising and Stabilising Luminescence in Halide Perovskite Device Structures Using Potassium-Halide Passivating Layers, Nature, 2018, 555, 497-501

SELECTED RECENT MEDIA:

• Energy Unplugged podcast - A conversation between Sam Stranks and Aurora Energy founder John Feddersen about PV and research (April 2022)
• How a new solar and lighting technology could propel a renewable energy transformation - Article in The Conversation by Sam (September 2020)
• Fast Nanoscale ‘Movies’ Shed Light on a Solar Cell Mystery - Article in WIRED about our article in Nature (April 2020)
• Interview with Sam Stranks about Perovskite based technologies' - Interview with Sam as featured on the Amp Hour Electronics podcast (March 2019)
• 'A new type of solar cell is coming to market', Article in the Economist about the commercialisation of perovskites (February 2018)
• 'Revolutionizing solar power with perovskites', keynote talk at Hello Tomorrow Summit (October 2017)
• '2017 could be the tipping point for super efficient solar panels', Article in WIRED World 2017 highlighting perovskites based on interview with Sam and his TED talk (January 2017)
• Our work on ‘Photo-induced halide redistribution in organic–inorganic perovskite films‘ was featured on the front page of the MIT and DOE websites, and highlighted by Nature as well as ScienceDaily, Phys.Org, ChemEurope.com and others (May 2016)
• An article on perovskites in Fast Company based on Sam's TED talk (March 2016)
• 'Uncovering a radical discovery in solar energy' TED Talk by Sam, TED conference Vancouver (February 2016)

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We acknowledge generous support from the European Research Council (HYPERION), the Royal Society, the Engineering and Physical Sciences Research Council, the Faraday Institute, the Leverhulme Trust and the European Commission.