UHasselt: Institute for Materials Research (IMO-IMOMEC) / Organic Opto-Electronics Research (OOE)

General expertise of the research group

The organic opto-electronics research group has the aim to solve fundamental questions in organic, hybrid and molecular electronics with relevance in opto-electronic devices such as OLEDs, sensors, solar cells and photovoltaic systems. The group is led by Prof. Dr. Ir. Koen Vandewal, who is well known for his seminal work on the characterization and description of charge-transfer states at organic interfaces. The groups expertise lies in the fabrication and characterization of thin film devices based on organic and hybrid perovskite materials, as well as advanced device characterization and device physics.

Specific hydrogen- related expertise & research topics

• Integration of organic and perovskite PV-elements with electrochemical cells.
• Engineering of photovoltaic interfaces.

Available equipment/tools:

• Glovebox with spincoater and thermal evaporator for sample and device preparation
• AM1.5g solar simulator
• Steady-state spectroscopy: UV/Vis/NIR transmission/reflection/absorption and photocurrent
• spectroscopy (350 nm – 2500 nm), emission (photoluminescence/electroluminescence/thermal) spectroscopy (350 nm – 20 um)
• Photothermal deflection and photoluminescence excitation spectroscopy with wavelength tuneable laser excitation (450 – 650 nm & 900 – 1300 nm)
• Time gated iCCD for time resolved spectroscopy (400 – 800 nm). 2 ns minimum gating time

Participating in FL/B/EU funded projects with H2 related research:

• CLEANH2 – Fundamental Research in Solar-driven Hydrogen Generation using Earth-abundant
• Catalysts and Durable Hybrid Perovskites as Light Absorbers, BOF.
• ConTROL – Charge-transfer states for high performance organic electronics, ERC Consolidator Grant
• Joint FWO project with HyMAT – Self-assembly of organic donor-acceptor complexes within the confinement of a perovskite lattice: a fundamental study of the relation between structure and opto-electronic properties. (R-11232)

International collaborations

• TU Dresden (device physics and engineering)
• Stanford University (Synchrotron x-ray analysis)

Main relevant publications

1. Emissive and charge-generating donor–acceptor interfaces for organic optoelectronics with low voltage losses. S. Ullbrich, J. Benduhn, X. Jia, V. C. Nikolis, K. Tvingstedt, F. Piersimoni, S. Roland, Y. Liu, J. Wu, A. Fischer, D. Neher, S. Reineke, D. Spoltore, K. Vandewal. Nature materials, 2019, 18.5: 459-464.
2.  Lead-Halide Perovskites Meet Donor–Acceptor Charge-Transfer Complexes. N. Marchal, W. Van Gompel, M. C. Gélvez-Rueda, K. Vandewal, K. Van Hecke, H-G. Boyen, B. Conings, R. Herckens, S. Maheshwari, L. Lutsen, C. Quarti, F. C. Grozema, D. Vanderzande, D. Beljonne. Chemistry of Materials, 2019, 31(17), 6880-6888.
3. High voltage vacuum-deposited CH3NH3PbI3–CH3NH3 PbI3 tandem solar cells. J. Ávila, C.
4.  Momblona, P. Boix, M. Sessolo, M. Anaya, G. Lozano, K. Vandewal, H. Míguez, H. J. Bolink. Energy & Environmental Science, 2018, 11(11), 3292-3297.
5. Intrinsic non-radiative voltage losses in fullerene-based organic solar cells. J. Benduhn, K. Tvingstedt, F. Piersimoni, S. Ullbrich, Y. Fan, M. Tropiano, K. A. McGarry, O. Zeika, M. K Riede, C. J. Douglas, S. Barlow, S. R. Marder, D. Neher, D. Spoltore, K. Vandewal. Nature Energy, 2017, 2(6), 17053.
6. Reducing voltage losses in cascade organic solar cells while maintaining high external quantum
7. efficiencies. V. C. Nikolis, J. Benduhn, F. Holzmueller, F. Piersimoni, M. Lau, O. Zeika, D. Neher, C. Koerner, D. Spoltore, K. Vandewal. Advanced Energy Materials, 2017, 7(21), 1700855.