Light Management in Optoelectronic Devices with Disordered and Chaotic Structures

• Main Author: Khan, Yasser
• Other Authors: Ooi, Boon S.
• Language: en
• Published: 2012
• Subjects: Light extraction; Light trapping; Quantifying disorder; Solid-state lighting; Energy harvesting; Microscopic Chaos
• Online Access: Khan, Y. (2012). Light Management in Optoelectronic Devices with Disordered and Chaotic Structures. KAUST Research Repository. https://doi.org/10.25781/KAUST-XL2DM; http://hdl.handle.net/10754/235351

With experimental realization, energy harvesting capabilities of chaotic microstructures were explored. Incident photons falling into chaotic trajectories resulted in energy buildup for certain frequencies. As a consequence, many fold enhancement in light trapping was observed. These ellipsoid like chaotic microstructures demonstrated 25% enhancement in light trapping at 450nm excitation and 15% enhancement at 550nm excitation. Optimization of these structures can drive novel chaos-assisted energy harvesting systems. In subsequent sections of the thesis, prospect of broadband light extraction from white light emitting diodes were investigated, which is an unchallenged but quintessential problem in solid-state lighting. Size dependent scattering allows microstructures to interact strongly with narrow-band light. If disorder is introduced in spread and sizes of microstructures, broadband light extraction is possible. A novel scheme with Voronoi tessellation to quantify disorder in physical systems was also introduced, and a link between voronoi disorder and state disorder of statistical mechanics was established. Overall, in this thesis some nascent concepts regarding disorder and chaos were investigated to efficiently manage electromagnetic waves in optoelectronic devices.