Projects

• "Stability of perovskite solar cells: identification and control of degradation processes" (Nr. 09.3.3-LMT-K-712-01-0031). 2018-2021. Principal investigator - Marius Franckevičius, main implementers: Vidmantas Gulbinas, Renata Karpič, Andrius Devižis, Andrej Dementjev, Egidijus Kamarauskas.
• “Next generation fluorescent viscosity sensors" (Nr. P-MIP-19-211). 2017-2019. Principal investigator - Aurimas Vyšniauskas.

Completed projects:

• “Influence of acceptor materials on charge carrier generation and motion in organic solar cells”, Research Council of Lithuania. 2015-2017. Head V. Gulbinas
• The best performing current state-of- the- art organic solar cells use fullerene-based electron acceptor mate rials. Attempts to use other, cheaper acceptor mate rials are less successful, and still remains not clear why. Recent investigations including our works revealed a relatively high electron mobility in fullerene materials, which is believed to be of the major importance for carrier generation and ,extract ion. Generally, charge carrier mobility and diffusion coefficient are among the most important parameters of electronic materials . In organic materials these parameters are typically much lower than in inorganic semiconductor.s., however strongly time-dependent; initially may be several orders of magnitude higher . In this project we will foe-us on the carrier generation and mobility dynamics in solar cells with acceptor materials based on polymers and small molecules with high electron affinity or semiconductor nanoparticles. The project aims at the development of the conceptional picture how the carrier generation and extract ion is related to the properties of electron accepting materials. We will apply photoelectrical and optical methods with ultrahigh time resolution, as well as advanced theoretical techniques to address the carrier generation mechanism and dynamics. The final task of the project is to formulate the requirements for the electron accepting materials enabling efficient operation of organic solar cells.
• ,,Metal organic perovskite photodetectors“, National research programme "Towards future technologies". Research Council of Lithuania. 2016-2018. Head R. Augulis
  High efficiency of metoloorganic perovskite solar cells achieved to date suggests that these materials may be successfully applied for light detectors as well. Owing to exceptional properties of perovskites and their fabrication technologies these detectors are expected to reach parameters comparable with those based on inorganic semiconductors and to have some unique properties, such as low price, large area, flexibility, compatibility with state of the art organic electronics circuits. Operation principles of solar cells and detectors are similar by many aspects, but there are several essential differences, which require different materials and device structures. There are several possible different architectures of perovskite-based photo detectors which may enable optimization of different parameters important for various applications .. The aim of this project is to investigate the applicability of CH3NH3PbX3 perovskites for light detectors, evaluation of viability of different device architectures and eventually, creation of a photodetector, which by some parameters could be be comparable or superior to commercially available conventional semiconductor detectors. During this project , we will gain expertise in new technologies of fabrication of metaloorganic perovskites and fabrication of their films, develop new charge transport materials, develop and adapt spectroscopic methods for investigation of perovskites and their devices. Consequently, the project will enable the gain of competence in a very modern and innovative area of new generation optical electronics and creation of infrastructure necessary for its further development.
• “Analysis of Photophysical Processes of Novel Light-emitting Aromatic Polymers Based on Fast Time-resolved Spectroscopy”, Lithuanian-Japan  science project. Research Council of Lithuania. 2017-2019.
  Head V. Gulbinas
  The project aims at development of photonic materials based on phthalimide compounds and polyimides.. Polyimides, due to their rigid structures and strong intermolecular interactions, are thermally and chemically stable materials with interesting thermal, mechanical, and optical properties. Moreover, their properties may be significantly varied by changing their chemical structures . It makes polyimides very interesting for creation of photonic materials for photovoltaic devices, organic light emitting diodes, functional liquid crystal alignment films, and solar spectrum converter. Luminescence properties of polyimides (quantum yield. spectrum ) may be varied by creating conditions for the excited sate internal proton transfer , aggregation, and interconversion transitions to triplet states. These processes take place simultaneously, interact and complete. Spectroscopic methods , particularly time resolved, are the major tool to get information about the electronic properties about materials and light induced processes necessary for development of advanced materials. We will investigate novel polyimides with different chemical structures with attached I, Br, and F atoms, which increase the internal conversion rate and influence the internal proton transfer. Ultrafast luminescence and transient absorption techniques :1i0 0 - e information about the rates of competing processes . Their dependences on the chemical structure, material morphology, temperature, a reveal their influence on the luminescence yields and spectra and possibilities to control them.