摘要(英) |
The looks, relatively in the traditional bulb, LED (Light Emitting Diode) has province electricity, environmental protection advantage, have claiming green to light. To the research of LED at present, mainly focus on improving light extracting efficiency and improving the ability of heat dissipation and white light LED realization. This research will be use sub-micro grating structure to improve light extract efficiency and modulate light pattern of LED. In this thesis, first to analyze of LED structure by simulation, and treat to how make sub-micro grating of different structure profile and different structure parameter on GaN-LED. Measurement light extraction efficiency by using PL (photoluminescence) to explain application of sub-micro grating on LED. To fabrication sub-micro grating by using E-beam lithography and dry etching, and using different dimension of sub-micro grating to discuss the influence of light extraction efficiency and light pattern. By simulation and measurement result, sub-micro grating can destroy waveguide mode of GaN epitaxy structure, let light extract from inside of structure. The structure of profile to trapezium or triangle of sub-micro grating can to increase light extract area from the bevel. The amount of light extraction and improve light extraction efficiency of LED advanced by the bevel structure.
Sub-micro grating changed light intensity distribution in airspace of LED. Let light pattern of lambertian distribution of LED modulated the uniform light pattern in within ±50 degree. We can use the notion that light pattern be uniform by sub-micro gratings. To appliance on back light of LED can improve the light source of LED be uniform.
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參考文獻 |
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