Engineering of gate-dielectrics for high-performance organic light emitting transistors [NANOLET]
Project Director: Dr. Carmen BREAZU
Project: PN-IV-P2-2.1-TE-2023-1626
Contractor: Institutul Național de Cerctare-Dezvoltare pentru Fizica Materialelor (INCDFM)
Project leader: Dr. Carmen Breazu
Project type:Research project to stimulate young independent teams (TE)
Start date: 08/01/2025
End date: 31/12/2026
Contracting Authority: UEFISCDI
Project Abstract
The multifunctional devices based on organic materials, including flexible integrated optoelectronics serve as a promising technology to realise user-friendly integrated electronic systems. Organic light emitting transistors/OLETs represent a relatively new technology platform in the field of organic electronics and have gained interest owing of unique integrated architecture which match electrical switching characteristics with the capability of generating light. High-performance is one of the key consideration for OLETs implementation and the research are devoted to studies of various physical processes implied in this organic devices and optimization of manufacturing techniques. In this regards, the project proposes a new configuration for OLET structures by dielectric/organic interface modification using a 2D nanostructures periodic arrangement and how this can be exploited as an active tool for light manipulation. Engineering of the surface provides a simple route for improved performance and/or increased functionality of OLETs structures and a step forward to overcome the limiting factors of their use in commercial electronics. The originality of the project derives from the nanotechnology method, UV-nanoimprint lithography proposed to be used for surface modification while the innovative aspect is covered by the new OLET configuration based on nanostructured surfaces.
Project leader: Dr. Carmen Breazu
Scientific researcher : Dr. Anca Stanculescu
Scientific researcher: Dr. Marcela Socol
Post-doctoral researcher: Dr. Oana Rasoga
Post-doctoral researcher: Dr. Andreea Costas
Post-doctoral researcher: Dr. Cristina Besleaga (Stan)
Doctoral student: Drd. Gabriela Baiasu
Executive summary of activities carried out during the implementation period
During phase 1/2025, five activities were carried out. Activity 1.1 Nanoimprint process – Design establishment; Ordering of nanoimprint masks; Fabrication of 2D nanostructure matrices (with different geometric parameters) on glass/flexible substrates. Within this activity, periodic arrangements of 2D nanostructures in the form of pyramids and pillars (cylinders) were fabricated on both rigid and flexible substrates, which were later used for the fabrication of organic light-emitting transistor (OLET) structures. Activity 1.2. a) Deposition of gate electrode and dielectric layer on selected nanostructured glass/flexible substrates. b) Characterization of nanostructured gate dielectrics. This activity followed the previous one, involving the deposition of dielectric films (PMMA and PDMS) by spin-coating on both rigid substrates and substrates with various patterning designs. The obtained dielectric films were investigated by profilometry, AFM, SEM, UV-VIS spectroscopy, FTIR, ellipsometry, and capacitance-voltage measurements. Activity 1.3 a) Deposition of organic layers on nanostructured gate dielectrics. b) Morphological, structural, optical, and electrical characterization of the active organic layers. c) Deposition of source and drain electrodes. This activity continued with the fabrication of the OLET structure, including the deposition of active multilayer films by MAPLE and the deposition of source and drain electrodes. The obtained organic films were characterized by atomic force microscopy, scanning electron microscopy, UV-VIS and photoluminescence spectroscopy, FTIR, and X-ray diffraction, confirming the successful realization of the active layer for the OLET structure. Activity 1.4 Fabrication of OLET structure on rigid nanostructured substrate. Electrical and optoelectronic characterization. In this activity, electrical measurements were performed on both planar and nanostructured transistor structures, revealing their properties. From a device design perspective, these results confirm that PMMA films and their nanostructured variants are suitable gate dielectrics for the OLET-TPD/BCP/Alq3 structure. Activity 1.5 Dissemination of results: Project website, participation in an international conference, submission of a paper for publication. This activity focused on disseminating the obtained results through participation in two international conferences, submission of two articles for publication in ISI-indexed journals, and the creation of the project website. Therefore, the deliverables, outcome indicators, and dissemination of results for 2025 have been fulfilled.
- C. Breazu,* A. Stanculescu, M. Socol, O. Rasoga, N. Preda, A. Costas, G. E. Stan, D. Georgeta Popescu, G. Petre, S. Iftimie, T. Tite, DNA−RNA Nucleobase-Coated ZnO Nanostructures for Interface Engineering in Organic Optoelectronics , ACS Applied Nano Materials, 2025, 8, 16307−16320.
- M. Socol, N. Preda, C. Breazu, S. Iftimie, G. Petre, A. Stochioiu, G. Popescu-Pelin, A. M. Catargiu, R. Udrea, G. Socol, A. Stanculescu, Metal phthalocyanine:perylene diimide derivative blend thin films deposited by MAPLE on rigid and flexible substrates submitted for publication in Applied Physics A. Manuscript number: APYA-D-25-03370
- C. Breazu, M. Socol, G. Petre, G. Socol, G. Popescu-Pelin, N. Preda, A.-M. Solonaru, M. Girtan, F. Stanculescu, O. Rasoga, A. Honciuc, A. Stanculescu, Effect of azomethine donor group on the properties of flexible bulk heterojunction with alkyl perylene diimide acceptor submitted for publication in in Journal of Materials Science. Manuscript number: JMSC-D-25-09470.
- Poster presentation: Nanostructured Gate/dielectric layers for Organic Light Emitting Transistors, C. Breazu, M. Socol, O. Rasoga, G. Petre, N. Preda, A. Costas, A. Stanculescu, C. Besleaga, G. Popescu-Pelin, G. Socol, la 15th International Conference & Exhibition on Green Flexible Printed Electronics Industry (ICEFPE25)and AGRIVOLTAICS 2025, Atena , Grecia
- Oral presentation: Influence de la composition de la couche active sur les paramètres des cellules solaires organiques, O. Rasoga, L. N. Leonat, Claudiu C. Constantin, S. Handor, E. Anate, Gabriela Petre, C. Breazu, S. Iftimie, M.Socol, 4e Symposium de la Recherche Scientifique Francophone en Europe Centrale et Orientale (SRSF-ECO), Université “Alexandru Ioan Cuza” 30-31 oct. 2025 Iași (Roumanie).
Contact person: Dr. Carmen Breazu
Phone: +40-765048588
Fax: +40-21369 0177
e-mail: carmen.breazu@infim.ro
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