| Abstract [eng] |
Approximately 19% of global energy consumption is dedicated to artificial lighting. Limited energy resources and increasing energy demands have underscored the need for more energy-efficient lighting devices and displays. Organic light-emitting diodes (OLEDs) have garnered significant scientific and commercial interest in recent decades due to their higher efficiency, simpler fabrication, flexibility, thinness, and potentially lower cost compared to inorganic counterparts. OLED devices are typically categorized into three generations: the first generation uses fluorescent emitters, the second generation employs phosphorescent noble metal complexes, and the third generation features thermally activated delayed fluorescence (TADF) emitters. This study involves synthesizing five new groups of carbazole and phenoxazine materials, examining their thermal and photophysical properties, and optimizing the solubility and layer-forming properties of the derivatives by varying the size of the aliphatic substituents. These materials were utilized in the emissive layers of all three generations of OLEDs, indicating several potential pathways for improving OLED technology. Some materials were synthesized using a simple, one-step process, suggesting the feasibility of scalable synthesis for yellow or candlelight OLED host materials. Additionally, the effectiveness of bicarbazole derivatives as both blue fluorescent emitters and host materials for green OLEDs has been demonstrated, with the best devices in this work achieving external quantum efficiencies of over 10%. |
