Over the past few decades, organic light-emitting diodes (OLEDs) have gained significant attention for their potential in solid-state lightingand flat-panel displays, due to their flexibility, cost-effectiveness, and high efficiency [1]. The development of novel organic emitters has become crucial to meet the growing demand for high-performance OLEDs in next-generation lighting and display technologies. The benzothiadiazole electron-withdrawing moiety, is commonly utilised in the design of organic emitters due to its rigid planar structure, which enhances emission performance [2]. Herein, we present the design and synthetic strategy for two novel compounds, synthesized through a straightforward, cost-effective single-step nucleophilic substitution reaction between the benzothiadiazole group and two different donors, 3,6-diphenyl-9H-carbazole and 10H-phenoxazine. Thermal, electrochemical, and photophysical properties of benzothiadiazole-based compounds are reported. Both compounds exhibit high temperatures of the onsets of thermal degradation and a high glass transition temperature, as well as optimum ionization potentials (IP). Photoluminescence (PL) studies revealed exceptionally high quantum yields. Time-of-flight charge mobility analysis confirmed the bipolar charge transporting properties of both the compounds, highlighting their potential as efficient electron- and hole-transporting materials. Considering the optimum IP and PL high emission quantum yields, they have the potential to be applied in OLEDs.
Keywords: OLEDs, benzothiadiazole, D-A-D-type fluorescence.