改質型鈣鈦礦量子點之合成與分析

Abstract

鈣鈦礦量子點具有發光強度高、放射峰半高寬窄、發光波長具可調控性等優點，是未來深具發展潛力的發光材料。在本研究中於室溫合成出發綠光的有機-無機鈣鈦礦量子點(CH3NH3PbBr3)，並且將其摻雜鎘離子，以求其發光特性及穩定性能得到改善。以電腦程式模擬的結果，預測由於生成能與能隙的變化，鎘離子摻雜後的量子點將能有更高的穩定性和發射波長位置。經過實驗分析後，證明有機-無機鈣鈦礦量子點於鉛離子位置，以10 mol%鎘離子取代後，發光強度上升，發光波長位置改變，色純度提升。將量子點加熱到高溫，發現升溫到80℃時的相對強度上升。成果證明鎘離子的摻雜能提升鈣鈦礦量子點的穩定性。將鎘離子摻雜的樣品封裝成白色發光二極體後，亦表現出優異的發光性質。未來將此研究的成果應用於作為顯示器背光源的白色發光二極體將能有前瞻性的進展。

The Perovskite quantum dots have the advantages of high luminescent intensity, narrow FWHM for emission peak, and adjustable luminescent central wavelength. Perovskite quantum dots based luminescent material has deep potential in the future. In this study, organic-inorganic perovskite quantum dots (CH3NH3PbBr3) were synthesized at room temperature, and doped with cadmium ions to improve their luminescence properties and thermal stability. Based on the simulation results of the density functional theory (DFT), the quantum dots doped with cadmium ions might showed higher stability. The red shift in luminescent central wavelength due to the changes in the formation energy and band gap was observed. The organic-inorganic perovskite with 10 mol % doping of cadmium ion showed increases in luminescent intensity. The shift in luminescent central wavelength and improvement in color purity was observed. The relative intensity of the sample increased when the temperature was raised to 80°C. The results demonstrated that the perovskite quantum dots doped with cadmium ions can improve the stability of perovskite quantum dots. After encapsulating the cadmium ion-doped sample into a white light-emitting diode, the white light-emitting diode also showed excellent light-emitting properties. The current work showed futuristic application as back light source in white light emitting diode.