| Summary: | 碩士 === 中原大學 === 化學工程研究所 === 107 === In recent years, white light-emitting diodes (W-LEDs) has drawn attention due to their high brightness, environmentally friendly, long lifetime, high energy efficiency, and less power consumption. Therefore, it is considered as the next generation light source. However, there have some problems for the phosphors used in LED, such as a broad width FWHM, low color purity and narrow color gamut area. Therefore, we need to develop a narrow FWHM quantum dot to enhance the color purity of the light-emitting diodes.
In this study, all-inorganic CsPbX3 (X=Cl, Br, I) perovskite quantum dots were synthesized via chemical colloidal synthesis and hot-injection method. Perovskite quantum dots are highly recognized due to their high photoluminescence properties, narrow lines and tunable wavelength; however, they are also known to have high sensitivity to moisture which leads to poor stability and unwanted anion exchange reactions. In order to resolve this, this study involves encapsulating CsPbBr3 with hydrophobic surface-modified mesoporous silica aerogel (CsPbBr3/PMSQ AG). This unique approach can not only enhance the stability of CsPbBr3 against moisture but also prevents anion exchange reactions. Water stability tests demonstrate that the as-synthesized CsPbBr3/PMSQ AG composites retained half of its initial intensity after soaking in water for more than 14 days. Then, packaged white light LED was obtained by combining green-emitting CsPbBr3/PMSQ AG and red-emitting K2SiF6:Mn4+ phosphor, and depositing onto a blue-emitting GaN-LED chip.
Also, Cs4PbBr6 which a derivative of CsPbBr3 was also studied. Cs4PbBr6 is a hexagonal structure of Cs4PbBr6 which can act as a protective barrier for CsPbBr3 quantum dots. Hence, Cs4PbBr6 can further improve the stability of CsPbBr3 and enhance its performance to further provide a better application for white light LEDs.
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