Quantum dot light-emitting diodes (QLEDs) have attracted intense attention since their inception due to their unique properties, such as tunable emitting wavelengths, saturated color and facile solution processability. Although the past decades have witnessed tremendous progress of QLEDs development as one of the most promising candidates for next-generation display technology, QLEDs remains to be outshined by state-of-the-art organic light-emitting diode (OLED) in efficiency, peak brightness and device lifetime. In this dissertation, we report that by employing a novel mixture of ZnO nanoparticles and Cs2CO3 as electron injection layer, hybrid and all-solution processed inverted QLEDs with ultra-high luminance, high current efficiency and low efficiency roll off can be realized. The devices surpass state-of-the-art OLEDs in terms of the peak luminance and electroluminescence efficiencies at high current densities. With the additional benefits of solution processability, low power consumption, and the structural compatibility with n-type transistor backplanes, these results are indicative of QLEDs' great potential for next-generation display. Beyond the application in display, other novel applications, which can take advantage of the unique features of these ultrabright red QLEDs without worrying about their relatively short lifetime, were also explored. We demonstrated, for the first time, that QLEDs can be promising light sources for various photomedical applications, including photodynamic therapy (PDT) cancer cell treatment and photobiomodulation (PBM) cell metabolism enhancement. The work promises to generate flexible QLED-based light sources that could enable the widespread use and clinical acceptance of photomedical strategies including PDT and PBM for the betterment of mankind. In addition, a hybrid white OLED design incorporating red quantum dot emitter is proposed and analyzed for high-performance solid-state lighting. Moreover, theoretical analysis shows the high potential of our ultra-bright QLED as light sources for high-performance optical sensors. The analysis paved the way for further developments of QLED-based technologies.
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Doctor of Philosophy (Ph.D.)
College of Optics and Photonics
Optics and Photonics
Optics and Photonics
Length of Campus-only Access
Doctoral Dissertation (Campus-only Access)
Chen, Hao, "Quantum Dot Light Emitting Devices (QLEDs) for Display, Lighting and Beyond" (2019). Electronic Theses and Dissertations, 2004-2019. 6863.