Sofiia Kosar, Ph.D.

Postdoctoral Fellows

Postdoctoral Fellow in De Wolf Group

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Research Interests

Sofiia’s research interests include understanding of property-function relationships between mesoscale properties of hybrid perovskites and macroscale performance of perovskite solar devices. During her PhD, Sofiia has investigated mesoscale processes in perovskite thin films by employing time-resolved photoemission electron microscopy (TR-PEEM). In particular, Sofiia imaged localized nanoscale surface defects in perovskite thin films, uncovered their varied nature and identified their roles in charge trapping and non-radiative recombination.

Further, Sofiia is interested in continuing with microscopic characterization to evaluate different levels of disorder in hybrid perovskite materials and in understanding of their impact on performance of perovskite solar cells.

Selected Publications

  • S. Macpherson, T. A. S. Doherty, A. J. Winchester, S. Kosar, D. N. Johnstone, Y. H. Chiang, K. Galkowski, M. Anaya, K. Frohna, A. N. Iqbal, S. Nagane, B. Roose, Z. Andaji-Garmaroudi, K. Orr, J. Parker, P. A. Midgley, K. M. Dani, S. D. Stranks, “Local Nanoscale Phase Impurities Are Degradation Sites in Halide Perovskites”, Nature, 607, 294-300 (2022).
  • S. Kosar, A. J. Winchester, T. A. S. Doherty, S. Macpherson, C. E. Petoukhoff, K. Frohna, M. Anaya, N. S. Chan, J. Madéo, M. K. L. Man, S. D. Stranks, K. M. Dani, “Unraveling the Varied Nature and Roles of Defects in Hybrid Halide Perovskites with Time-Resolved Photoemission Electron Microscopy”, Energy Environ. Sci., 14, 6320-6328 (2021).
  • T. A. S. Doherty, A. J. Winchester, S. Macpherson, D. N. Johnstone, V. Pareek, E. M. Tennyson, S. Kosar, F. U. Kosasih, M. Anaya, M. Abdi-Jalebi, Z. Andaji-Garmaroudi, E. L. Wong, J. Madéo, Y. H. Chiang, J. S. Park, Y. K. Jung, C. E. Petoukhoff, G. Divitini, M. K. L. Man, C. Ducati, A. Walsh, P. A. Midgley, K. M. Dani, S. D. Stranks, “Performance-Limiting Nanoscale Trap Clusters at Grain Junctions in Halide Perovskites”, Nature, 580, 360-366 (2020).
  • C. E. Petoukhoff, S. Kosar, M. Goto, I. Bozkurt, M. Chhowalla, K. M. Dani, “Charge Transfer Dynamics in Conjugated Polymer/MoS2 Organic/2D Heterojunctions”, Mol. Syst. Des. Eng., 4, 929-938 (2019).
  • S. Kosar, Y. Pihosh, R. Bekarevich, K. Mitsuishi, K. Mawatari, Y. Kazoe, T. Kitamori, M. Tosa, A. B. Tarasov, E. A. Goodilin, Y. M. Struk, M. Kondo, I. Turkevych, “Highly Efficient Photocatalytic Conversion of Solar Energy to Hydrogen by WO3/BiVO4 Core–Shell Heterojunction Nanorods”, Appl. Nanosci., 9, 1017-1024 (2019).

Education

  • Ph.D., Okinawa Institute of Science and Technology Graduate University, Onna-son, Japan, 2022.
  • M.S., Condensed Matter Physics, Chernivtsi National University, Chernivtsi, Ukraine, 2017.
  • B.S., Physics, Chernivtsi National University, Chernivtsi, Ukraine, 2015.

Professional Profile

  • Mar. 2023 – present: Postdoctoral Fellow, KAUST, Thuwal, Saudi Arabia.
  • Oct. 2022 – Feb. 2023: Junior Research Fellow, Okinawa Institute of Science and Technology Graduate University, Onna-son, Japan.

KAUST Affiliations

  • ​KAUST Solar Center (KSC)
  • Division of Physical Science and Engineering (PSE)​

Research Interests Keywords

Perovskite photovoltaics spatially-resolved characterization photophysics