Spin and Excitonics Engineering Group (Advisor: Marc A. Baldo)Concentration: triplet-triplet annihilation(TTA) for photon upconversion and organic light emitting diodes (OLED)1. High-performance solid-state TTA photon upconversion- In-depth device physics study through spectroscopy techniques: photoluminescence (PL), phosphorescence, transient PL, magnetic-field-modulated PL, external quantum efficiency (EQE) via integrating sphere- Identified a loss pathway specific to solid-state system in addition to known losses in other phases- Introduced OLED materials and device architecture to mitigate losses in photon upconverters- Incorporated Fabry-Perot cavity to enhance optical absorption and significantly improved upconversion performance- Originated bulk perovskite-sensitized TTA upconversion in collaboration with chemists2. TTA for highly stable blue OLEDs- Investigate potential breakthrough for conventional TTA efficiency limit in collaboration with theoretical chemists- Develop a new method to characterize TTA efficiency of a dye based on OLED- Build highly stable blue OLED with emitters having efficient TTA

- Teach tutorial sessions, grade assignments, and help clarify lecture contents

Display Investigations TeamDeveloped validation programs for customer facing features on Apple products

Group of Organic Optronics and Displays (Advisor: Chung-Chih Wu)Concentration: Pure Blue and White OLEDs based on Thermally Activated Delayed Fluorescent (TADF) Materials- Built single-emitting-layer white OLEDs with efficiency >32% and color rendering index of >80 based on efficient blue TADF OLED

Group of Organic Optronics and Displays (Advisor: Chung-Chih Wu)Concentration: investigation of photo-physical properties and device applications of thermally activated delayed fluorescent (TADF) materials for OLEDs- Photo-physical and optical properties of novel TADF materials: PL, phosphorescence, PL quantum yield, time-resolved and temperature-dependent PL, emitting dipole orientation, anisotropic optical constants (ellipsometry)- Developed then-record-efficiency sky blue TADF OLED: designed OLED structure through optical simulation; Fabricated and characterized device performance (I-V-L, electroluminescence, EQE, operation lifetime)