Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV24)
Publication date: 6th February 2024
Our group developed photoluminescence (PL) measurement solutions addressing defect identification of organic PV (OPV) structures and devices. The photo-response of the absorber materials was investigated with dynamic and static PL measurements aiming the industrial application of these techniques.
The dynamics of the photo-response of the OPV samples were studied using Time Correlated Single Photon Counting (TCSPC) measurement technique. The unique feature of the TCSPC technique is to obtain the time-resolved fluorescence dynamics of molecular orbit transitions at extremely low injection conditions.
The luminescence decay characteristics featured very short, 100-500 ps decay component. Such fast dynamics might not be detected using a conventional photodiode-based measurement system. Although the signal amplitude depends on the structural properties, but the evaluated decay time relates only to the given molecular specie of the absorber layer.
The industrially more important and viable technique is the PL imaging to detect problems with layer deposition. Therefore, we present the key steps of the development of roll-to-roll imaging PL characterization of organic PV structures.
The proper choice of the excitation light source type, wavelength, power together with the very efficient light management made possible to build several experimental measuring setups with different cameras and filter sets to define the optimal configuration of the integration-ready PL imaging system.
The final PL configuration using line cameras and recording PL images from large area samples was finally proven to provide outstanding quality and resolution images from all relevant organic layers and clearly indicating its unique capability for the real-time revealing of homogeneity issues in the layer deposition processes. The system optimization resulted in a fast-enough image capturing ensuring the easy adoption of the imaging PL technique in organic PV production lines.
This work was supported by In-line and Real-time digital nano-characterization technologies for the high yield manufacturing of Flexible Organic Electronics ’ — ‘RealNano’.
Grant Agreement number: 862442 — RealNano — H2020-NMBP-TO-IND-2018-2020 / H2020-NMBP-TO-IND-2019 a Horizon 2020 funded EU project.
This research was supported by the NKFIH grants 2022-2.1.1-NL-2022-00004, KDP-IKT-2023-900-I1-00000957/0000003 and by the János Bolyai Scholarship of the Hungarian Academy of Sciences.