The development of efficient organic light emitting diodes (OLED) based on the phenomenon of intramolecular thermally activated delayed fluorescence (TADF), in the design of which there are no blue phosphorescent emitters based on rare earth metals, still remains a challenge in the development of new lighting systems and OLED displays. The article proposes a technological approach to the formation of new type of OLED, where the emitter is an organic donor-acceptor molecular material 9-(2,3,5,6-tetrachloropyridin-4-yl)-9H-carbazole (4-CzPyCl4), in which electronic interaction between the donor and acceptor fragment plays a key role in the mechanism of delayed fluorescence. The design of the developed light-emitting heterostructure uses layer-by-layer formation of functiona nanosized organic films, in contrast to traditional OLED designs of dark blue color radiation, which uses a guest-host systemThe external quantum efficiency of the developed OLED is 2.8 %. The maximum brightness of 3,000 cd/m2 is reached at a voltage of 15 V. The chromaticity coordinates CIE (x, y) 1931 are (0.15, 0.13), which corresponds to the “dark blue” emitting spectral zone.
 G. Schwartz, M. Pfeiffer, S. Reineke, K. Walzer and K. Leo. Adv. Mater (2007), Harvesting Triplet Excitons from Fluorescent Blue Emitters in White Organic Light-Emitting Diodes, (19), 3672–3676.
 ENERGY STAR Requirements for SSL Luminaires, Version1.1, ENERGY STAR requirements for integral LED lamps,U.S. Department of Energy, (2007).
 C. W. Han, W. Tak and B. C. Ahn J. (2007), Society information display.(19), 190–195. The development of non-doped OLED based on donor-acceptor… Information and communication technologies, electronic engineering. Vol. 1, No. 2, pp. 123–130 (2021) 129
 H. Uoyama, K. Goushi, K. Shizu, H. Nomura, C. Adachi (2012), Nature, Highly efficient organic light-emitting diodes from delayed fluorescence , (492), 234–238.
 G. Schwartz, S. Reineke, K. Walzer and K. Leo. (2008) Reduced efficiency roll-off in high-efficiency hybrid white organic light-emitting diodes Appl. Phys. Lett., (92).
 H. Sasabe, J. Takamatsu, T. Motoyama, S. Watanabe, G. Wagenblast, N. Langer, O. Molt, E. Fuchs, C. Lennartz and J. Kido (2010), High-Efficiency Blue and White Organic Light-Emitting Devices Incorporating a Blue Iridium Carbene Complex, Adv.Mater.(22), 5003–5007.  Y. Im, M. Kim, Y. J. Cho, J.-A. Seo, K. S. Yook, J. Y. Lee (2017), Molecular Design Strategy of Organic Thermally Activated Delayed Fluorescence Emitters, Chem. Mate (29), 1946–1963.
 Y. Seino, S. Inomata, H. Sasabe, Y. Pu, J. Kido (2016), High-Performance Green OLEDs Using Thermally Activated Delayed Fluorescence with a Power Efficiency of over 100 lm W-1, Adv. Mater. (28), 2638–2643.
 Organic electronics: a textbook / G. V. Baryshnikov, D. Yu. Volyniuk, I. I. Helzhinsky [etc.]; for ed. Z. Yu. Gotri. Lviv: Lviv Polytechnic Publishing House, 2019. 292 p.
 L.-S. Cui, H. Nomura, Y. Geng, J. U. Kim, H. Nakanotani, and C. Adachi (2016), Controlling Singlet-Triplet Energy Splitting for Deep-Blue Thermally Activated Delayed Fluorescence Emitters, Appl. Chem. (56), 1571–1575.
 Y. Danyliv, R. Lytvyn, D. Volyniuk, I. Hladka, J. V. Grazulevicius (2018), Derivatives of carbazole and chloropyridine exhibiting aggregation induced emission enhancement and deep-blue delayed fluorescence,Dyes and Pigments, (149), 588–596.
 Elements and devices of organic electronics: a collective monograph / G. V. Baryshnikov, I. I. Gelzhinsky, Z. Yu. Gotra, H. B. Ivanyuk, B. P. Minaev, P. Y. Stakhira. Lviv: Space-M, 2020. 224 p.
 Organic light-emitting structures: collective monograph / G. V. Baryshnikov, I. I. Gelzhinsky, Z. Yu. Gotra, H. B. Ivanyuk, B. P. Minaev, P. Y. Stakhira. Lviv: Lviv Polytechnic Publishing House, 2020. 236 p.
 P. Y. Stakhira, V. V. Cherpak (2009), The properties of heterojunction based on CuI/pentacene/Al, Vacuum, 83 (8), 1129–113.
 I. Hladka, R. Lytvyn, D. Volyniuk, D. Gudeika, J. V. Grazulevicius (2018), W-shaped bipolar derivatives of carbazole and oxadiazole with high triplet energies for electroluminescent devices, Dyes and Pigments (149),812–821.
 X. Tan, D. Volyniuk, T. Matulaitis, J. Keruckas, K. Ivaniuk, I. Helzhynskyy, P. Stakhira, J. V. Grazulevicius (2020), High triplet energy materials for efficient exciplex-based and full-TADF-based white OLEDs, Dyes and Pigments (177), 108259.
 Y. Danyliv, D. Volyniuk, O. Bezvikonnyi, I. Hladka, K. Ivaniuk, I. Helzhynskyy, P. Stakhira, A. Tomkeviciene, L. Skhirtladze, J. V. Grazulevicius (2020), Through-space charge transfer in luminophore based on phenyllinked carbazole- and phthalimide moieties utilized in cyan-emitting OLEDs, Dyes and Pigments (172), 107833.
 S. H. Eom, Y. Zheng, E. Wrzesniewski, J. Lee , N. Chopra, F. So and J. G. Xue (2009), White phosphorescent organic light-emitting devices with dual triple-doped emissive layers, Appl. Phys. Lett. (94) 3.
 N. Aizawa, M. Numata, C. Adachi, T. Yasuda (2017), Versatile Molecular Functionalization for Inhibiting Concentration Quenching of Thermally Activated Delayed Fluorescence, Adv. Mater. (29), 1604856.
 Q. Zhang, D. Tsang, H. Kuwabara, Y. Hatae, B. Li, T. Takahashi, S. Y. Lee, T. Yasuda, C. Adachi (2015), Nearly 100 % Internal Quantum Efficiency in Undoped Electroluminescent Devices Employing Pure Organic Emitters,Adv. Mater. (27), 2096.
 G. Barylo, Helzhinsky I. I., Golyaka R. L., Marusenkova T. A., Khilchuk M. O. (2021), Built-in system of converter of supply voltage of organic light-emitting diodes, Bulletin of Khmelnytsky National University. No. 2(295). pp. 151–155.
 G. І. Barylo, R. L. Holyaka, I. І. Helzhynskyy, Z. Yu. Hotra, M. S. Ivakh, R. L. Politanskyi (2020), Modeling of organic light emitting structures, Physics and Chemistry of Solid State Open Access, Vol. 21, Is. 3, рр. 519–524, 30 September 2020. DOI:10.15330/PCSS.21.3.519-524/
 G. Barylo, O. Boyko, I. Gelzynskyy, R. Holyaka, Z. Hotra, T. Marusenkova, M. Khilchuk, M. Michalska (2020), Hardware and software means for electronic components and sensors research, IAPGOŚ Informatyka, Automatyka, Pomiary W Gospodarce I Ochronie Środowiska. No. 10(1). pp. 66–71.