HYPOTHESIS
NAME – Deepti Sahu
My current interest of research is on synthesis and device fabrication of TADF (Thermally
Activated Delayed Fluorescence) emitters. With the introduction of TADF emitters has
ushered in a new era of energy-efficient, versatile, and durable displays and lighting
solutions. With their exceptional efficiency, expanded colour range, prolonged lifespan,
compatibility with flexible and transparent substrates, and applications in healthcare and
biotechnology, TADF emitters have become indispensable in shaping the present and future
of technology.
There are many challenges faced in this emerging field of research, their operation and
underlying mechanisms that remain poorly understood, ensuring long-term stability of TADF
materials to make good OLED devices, scaling up its synthesis at commercial level is a crucial
area of research etc. Optimizing the efficiency, lifetime, and luminous efficacy of TADF-based
devices requires overcoming various engineering hurdles, such as developing efficient
charge transport layers, improving charge injection and extraction, and minimizing exciton
quenching at interfaces. We want to address some of these problems.
TADF emitters exhibit nearly 100% internal quantum efficiency, this high efficiency is
achieved by utilizing both singlet and triplet excitons, which significantly reduces energy
wastage. In contrast, conventional emitters, such as phosphorescent and fluorescent
materials, often have lower internal quantum efficiencies. There are several papers
confirming this property by having a donor and acceptor molecule giving high efficiency. One
of the paper is Thermally Activated Delayed Fluorescence Emitters with A m,m-Di-Tert-ButylCarbazolyl Benzoylpyridine Core Achieving Extremely high Blue Electroluminescence
Efficiencies, P. Rajamalli, V. Thangaraji, N. Senthilkumar, C.-C. Ren-Wu, H.-W. Lin, and C.-H.
Cheng, J. Mater. Chem. C 5, 2919 (2017)