發光二極體光取出效率提升方式探討與新式固態雷射照明光源開發與應用

Abstract

本論文分為前後兩部分，第一部份的內容主要探討提升發光二極體的光取出效率的方式，首先我們利用半導體製程的黃光微影以及耦合電漿蝕刻製程在LED晶片的表面透明導電層製作出微結構(patterned ITO)，分析透明導電層微結構的導入與LED晶片光輸出強度的關係，從分析的結果顯示，LED晶片的光輸出強度在patterned ITO導入後有明顯的增益，整體的增益提升了2.7%。 接著我們利用光追跡(ray tracing)模擬軟體分析半球形LED封裝體的幾何結構與光取出效率的關係，經由分析結果顯示，適當的半球形幾何可以有效的提升LED光取出效率。 第二部分我們成功的利用可見光雷射二極體結合螢光體產生出高輝度的白光點光源，最高的輝度可以達到445.8 cd/mm2，利用此高輝度雷射點光源，我們設計出高投射距離的光機系統，該光機系統的5公尺投射照度為13996lx，估算1 iso-lux投射距離為591.5公尺。並於最後，我們利用雷射白光光源的特性提出了新形態的行車智慧照明系統概念以及模擬結果。

In this thesis, it is separated into two part. In the first part, we have focus on improving light extraction efficiency of LED. The investigation starts at surface patterning of LED chips. By using photolithography and ICP etching, we can fabricate patterned ITO on LED chip. As a result, the output intensity of LEDs with patterned ITO are 2.7% higher compare to reference samples. After the investigation of surface patterning of LED chips, we use ray tracing simulation software to optimize encapsulated lens dimension of LED package. From the simulation results, we construct a formula of encapsulated lens dimension which can provide high light extraction efficiency with controllable radiation pattern. By applying the results from our investigation, a high light extraction efficiency LED can be provided. At the second part, a new high luminance white point light source generated by visible laser diode is developed and provided. The luminance of laser white light achieves 445.8 cd/mm2. Using the high luminance laser white light source, we construct a compact light projecting system designed by ray tracing simulation software. After measurement, the light projecting system shows the center illuminance is 13996lx on the screen 5m far from light source. The estimating 1 iso-lux project distance is 591.5m. In the mean time, an automotive smart lighting concept is illustrated in the end of this thesis.