Executive Summary : | The scientific objectives of this research are to develop cost-effective Organic Light Emitting Diode (OLED) technology for display and lighting applications. The research will focus on designing exciplex/electroplex/electromer as the host for novel TADF emitters, investigating photophysical properties and emitter orientation of synthesized TADF emitters, fabricating OLED devices using developed blue TADF emitters in an exciplex/electroplex/electromer host matrix, understanding factors affecting the stability of novel device structures, and conducting cost-benefit analysis compared to expensive phosphorescent devices.
The research will use TD-DFT calculations and Tamm-Dancoff approximation to accurately predict the properties of TADF systems. The study will also explore the synthesis of selected TADF emitters with a small λEsT 0.1-0.2 eV, strong oscillator strength, and longer horizontal axis length to width aspect ratio 1.5.
Photophysical properties of synthesized TADF materials will be investigated using various instrumentation techniques, including UV-Vis spectroscopy, fluorescence spectroscopy, phosphorescence spectroscopy, TCSPC, time-resolved emission spectrum, thermogravimetric analysis, and differential scanning calorimetry. The selection of host molecule and substrate temperature will be optimized to align the orientation of TADF molecules horizontally in a host matrix, enhancing light outcoupling and efficiency of OLED devices.
The expected results include new blue-emitting highly efficient TADF systems with PL quantum yields 75 λPF λDF, EsT 0.1-0.2 eV, length-to-width aspect ratio 1.5, horizontal transition dipole ratio 90, FWHM 30-35 nm, a novel synthetic route to realize designed TADF systems, blue emissive OLED devices with maximum external quantum efficiency EQEmax 20, maximum luminance brightness 10,000 cd/m2, and CIE coordinates close to pure blue emission 0.15, 0.1. |