全無機型鈣鈦礦量子點及其衍生物的合成、鑑定與其在白光發光二極體及量子點增色膜的應用

Abstract

本論文著重於合成全無機型CsPbX3(X = Cl, Br, I)鈣鈦礦量子點並分析其發光性質與特性鑑定，其晶體結構為立方結構，且具有結晶性好、單一粒徑分布、尺寸分布窄等特性。此外，因具備量子侷限效應，故可以透過調控粒徑大小與調控鹵素陰離子的組成來控制其放光波長，其放光明亮且穩定，並具有高量子效率、窄放光峰、放光波長可調控且涵蓋整個可見光範圍的優點。為了應用於量子點增色膜與白光發光二極體，因此選擇發綠光CsPbBr3量子點與發紅光CsPb(Br0.4I0.6)3量子點透過APTES ((3-Aminopropyl)triethoxysilane)及TMOS (Tetramethyl orthosilicate)水解反應各別在其外圍包覆二氧化矽以增加其穩定性且可避免綠色與紅色量子點混合時發生之陰離子交換反應，並對其作穩定性、放光性質與特性鑑定，研究成果顯示其可成功提升量子點之熱穩定性與光穩定性。此量子點二氧化矽衍生物應用有二：第一、將綠色CsPbBr3@SiO2、紅色CsPb(Br0.4I0.6)3@SiO2與藍光LED晶片作白光發光二極體(WLED)封裝，量測其應用於WLED之效能與色域覆蓋率，以期能達到廣色域與高色彩飽和度之目標，未來可實際應用於背光顯示系統；第二、將綠色CsPbBr3@SiO2與紅色CsPb(Br0.4I0.6)3@SiO2混合分散在聚苯乙烯高分子溶液中，透過旋轉塗佈方式製成量子點增色膜，並對膜的放光性質作分析，研究成果顯示此量子點二氧化矽衍生物成功避免綠色與紅色量子點混合時發生之陰離子交換反應，此成果對未來應用於背光顯示有很高潛力。

This research focuses on the chemical synthesis and characterizations of all-inorganic CsPbX3 (X = Cl, Br, I) cubic and well-crystalline perovskite quantum dots (QDs), based on which white-light LEDs and color-enhancement films were fabricated. Luminescent QDs have been known to exhibit high PLQY, narrow emission and tunable emissions ranging in the UV to Vis spectral range, which were attributed to quantum confinement effect. To improve material stability and investigate potential optoelectronic applications, We have prepared and characterized SiO2-encapsulated green-emitting CsPbBr3 and red-emitting CsPb(Br0.4I0.6)3 QDs through the hydrolysis of APTES ((3-Aminopropyl)triethoxysilane) and TMOS (Tetramethyl orthosilicate), respectively. Our results revealed that the thermal and photostability of perovskite QDs have been successfully improved. We have dispersed green- and red-emitting perovskite QDs in solutions of PS polymers and then spin-coated to form QD color-enhancement films whose luminescent properties were both evaluated and compared. On the other hand, WLEDs were also fabricated by integrating green SiO2-encapsulated CsPbBr3 QDs, red SiO2-encapsulated CsPb(Br0.4I0.6)3 QDs and blue LED chips and evaluated for practical application. Our research has concluded that encapsulation of SiO2 on QD prohibits anion exchange between QDs with different colors, which aids and realizes the practical application of QDs in color enhancer of display backlight units.