Kinetic processes in organic and hybrid compounds

Principal Investigators:
  • Dr. Renata Karpicz 
  • Dr. Andrius Devižis 
  • doktr. Lena Golubeva

Application of organic and hybrid materials in optoelectronic devices such as sensors, organic light-emitting diodes, solar cells requires detailed knowledge of their spectroscopic properties and understanding of excited state and carrier dynamics. At the molecular level, the distances between different objects are of the order of angstroms or nanometers.  Accordingly, processes are very fast, many of them occurring on a picosecond or femtosecond time-scales. Ultrafast spectroscopy is a major tool enabling to follow these processes and to investigate their mechanisms and dynamics. We developed a femtosecond laser system for transient absorption and luminescence investigations. We also use the dynamic Stark effect to flow ultrafast charge carrier motions. Furthermore, we use a two-dimensional coherent electron spectroscopy setup for special tasks that require not only high time resolution but also high spectral resolution. When using a closed-loop helium cryostat, measurements can be made by cooling the samples to 10 K. This provides additional information on the behavior of the investigated compounds at different temperatures, which facilitates the development and validation of theoretical models.

The objects range from perovskite materials, organic photovoltaics devices and nanostructured materials to proteins.


Major publications
  1. U. Bubniene, R. Mazetyte, A. Ramanaviciene, V. Gulbinas, A. Ramanavicius and R. Karpicz „Fluorescence Quenching-Based Evaluation of Glucose Oxidase Composite with Conducting Polymer, Polypyrrole“ J. Phys. Chem. C 122 (2018) pp. 9491-9498.
  2. A.Bukauskytė, R.Karpicz, R.Striela, L.Labanauskas, A.Gruodis, D.Peckus, R.Augulis, V.Gulbinas. „The influence of substituents of perylenediimides on their spectroscopic properties“ J. Lumin. 195 (2018) pp. 252-258.
  3. K.Chernyakova, R.Karpicz, S.Zavadski, O.Poklonskaya, A.Jagminas, I.Vrublevsky “Structural and fluorescence characterization of anodic alumina/carbon composites formed in tartaric acid solution” J. Lumin. 182 (2017) p. 233-239.
  4. A. Fakharuddin, W. Qiu, G. Croes, A. Devižis, R. Gegevičius, A. Vakhnin, C. Rolin, et al. ‘Reduced Efficiency Roll‐Off and Improved Stability of Mixed 2D/3D Perovskite Light Emitting Diodes by Balancing Charge Injection’. Advanced Functional Materials, 2019, 1904101.
  5. A. Devižis, J. De Jonghe-Risse, R. Hany, F. Nüesch, S. Jenatsch, V. Gulbinas and J.-E. Moser. ‘Dissociation of Charge Transfer States and Carrier Separation in Bilayer Organic Solar Cells: A Time-Resolved Electroabsorption Spectroscopy Study’. Journal of the American Chemical Society, 2015, 137, no. 25 : 8192–98.