高顏色轉換效率之膠體量子點發光二極體封裝於二氧化矽多孔性微球之研究

Abstract

量子點在現今顯示技術中扮演的角色日益重要， 在光電領域中被廣泛應用，包括發光二極體 (LED)、顯示器、太陽能電池和生物成像等。量子點具備高亮度、色域廣、半高寬窄和良好的穩定性等優點 ，使其成為提升顏色轉換效率和光學性能的理想材料。不過，量子點的自聚集和再吸收效應可能影響其應用性能，需要透過精細的封裝和材料選擇來進行優化。 本論文中，我們使用的 LED 導線架規格為 5050，實驗前後皆會用積分球量測LED 的光譜、光強度及發光效率等。而實驗中，我們主要使用硫化鋅包覆硒化鎘量子點甲苯溶液及二甲基矽氧甲烷(PDMS) ，與多孔二氧化矽微球混合 ，用“膠體混合”以及 “層狀結構+”兩種不同的封裝結構與之前的樣品比較其光譜及顏色轉換效率之變化。 實驗結果顯示，只有 PDMS 混合膠體量子點的樣品的顏色轉換效率較以往又更進步了一些，而“膠體混合”封裝在中、低濃度時，多孔二氧化矽微球的顏色轉換效率也相較以往使用微載體進行混合時提升了不少;至於“層狀結構+”封裝，多孔二氧化矽微球在中濃度時較微載體好上許多，但到了高濃度時，則有略為下降的趨勢。

Quantum dots play an increasingly important role in modern display technology and are widely used in the optoelectronic field, including applications such as light-emitting diodes (LEDs), displays, solar cells, and bio-imaging. Quantum dots offer advantages such as high brightness, a wide color gamut, narrow full-width at half-maximum (FWHM), and excellent stability, making them ideal materials for improving color conversion efficiency and optical performance. However, quantum dot self-aggregation and reabsorption effects may impact their performance, necessitating optimization through precise encapsulation and material selection. In this study, we used LED lead frames with 5050 specifications and measured the spectrum, light intensity, and luminous efficiency of the LEDs with an integrating sphere before and after the experiments. The primary materials used in the experiments included cadmium selenide (CdSe)-coated zinc sulfide (ZnS) quantum dots in toluene solution and polydimethylsiloxane (PDMS), mixed with porous silica microspheres. We compared the spectral and color conversion efficiency (CCE) changes using two different encapsulation structures, "mixed" and "layered+," against previous samples. The experimental results showed that samples with colloidal quantum dots mixed solely with PDMS exhibited further improvements in color conversion efficiency compared to previous iterations. For "mixed" encapsulation, the color conversion efficiency of porous silica microspheres at medium and low concentrations was significantly enhanced compared to mixing with microcarriers in the past. Regarding the "layered+" encapsulation, porous silica microspheres performed much better than microcarriers at medium concentrations but exhibited a slight decline at high concentrations.