近年來鈣鈦礦量子點在顯示器及光電產業受到大量關注，從眾多材料中脫穎而出，成為新一代顯示器未來相當具有發展潛力的材料，這些都歸功於鈣鈦礦優異的光電特性，例如：色域覆蓋面積大、螢光放光半高寬較窄、發光波長具有高度可調變性、近100%的螢光量子轉換效率等。雖然鈣鈦礦量子點的光電性質近乎完美，卻容易受到水、氧氣、連續紫外光照射等外在環境的影響而改變其自身的光電特性，使得鈣鈦礦材料至今仍無法順利進行商用化。針對改善鈣鈦礦量子點的穩定性，過去本團隊研究導入硫酸根奈米纖維素晶體取代傳統有機長碳鏈之配體，以增強鈣鈦礦量子點與配體間的鍵結強度，從而達到高穩定性的目標。雖然在穩定性方面得到顯著改善，但在製程中形成的大晶體卻會導致螢光量子轉換效率降低。因此，本研究在鈣鈦礦量子點與奈米纖維素晶體的製程中加入苯乙銨鹵化物，提供過量鹵素並且增強量子侷限效應，並轉變為二維鈣鈦礦之結構。最終使CsPbBrI2螢光複合膜的螢光量子效率提升18倍、CsPbBr3螢光複合膜提升3倍以及CsPbBr1.5Cl1.5螢光複合膜提升8倍，期許對下一世代穩定且高轉換效率的顯示技術提出貢獻。

Recently, perovskite quantum dots (PQDs) have drawn lots of attention in the display technology field due to outstanding optoelectronic properties such as wide color gamut, high photoluminescence quantum yield (PLQY), and tunable emission wavelength. Despite the above advantages, PQDs still suffer from instability against oxygen, moisture, and continuous ultra-violet irradiation, which greatly impede the commercial applications. To enhance the stability of the PQD films, we have applied surface functionalized cellulose nanocrystals (CNCs) to substitute traditional ligands for improving the binding strength between the ligands and PQDs. However, the PLQY in such films are limited due to large crystals formed during the synthesis process. In this study, we incorporate phenethylammonium halide (PEAX, where X = Cl, Br, and I) during the synthesis process, and the PLQYs of CsPbBr1.5Cl1.5, CsPbBr3, and CsPbBrI2 films with PEAX passivation can be improved more than 8 (from 1.2% to 10%), 3 (from 22% to 69%), and 18 (from 3% to 55%) times, respectively, since the phenethylammonium halide provides a halide-rich environment and a more significant quantum confinement effect to PQDs in the CNC films. By combining the advantages of CNC and PEAX, stable light emission/conversion films with largely increased PLQY can be achieved. As a result, the synergistic approach of CNC and PEAX passivations for light emission/conversion films demonstrated herein holds the potential for developing full-color, stable, and high PLQY next generation applications in the future.

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