利用流道化學系統精準合成全無機碘化物鈣鈦礦量子點與其高效光電元件應用

Abstract

全無機碘化物鈣鈦礦量子點 (CsPbI3 perovskite quantum dots; PeQDs) 因具備高光致發光量子效率 (photoluminescence quantum yield, PLQY)、窄半高波寬及可調能隙等優勢，近年廣泛應用於顯示與光電元件。然其表面缺陷、長鏈配體所造成之載子傳輸阻隔及材料本身之環境穩定性不足，仍限制其於實際元件中之應用表現。故維持高發光效率之同時改善電荷傳輸與材料穩定性，為當前重要研究課題。 本研究以連續式流道化學系統 (fluidic chemistry system) 精準調控反應條件以合成高效率 CsPbI3 PeQDs。並由使用短鏈 benzothiazole-based 配體具 N、S 雜原子與共軛芳香結構，可有效鈍化表面缺陷、提升電荷傳輸並增強發光效率與穩定性。所合成之 PeQDs 具接近 100% 之 PLQY 與優異光學穩定性，於長時間環境測試下 70 天後仍可維持 PLQY 98% 之穩定發光表現。 本研究將一系列材料應用於 LED 背光與 Micro-LED 色轉換層。於 CIE 色彩空間中可達 NTSC 1931 約 148.7% 之高色域覆蓋率。於微影製程實現高解析度 Micro-LED，驗證其於高像素密度顯示技術之應用潛力。光電偵測器應用方面，將 PeQDs 導入 ZnO nanorods 元件後，可顯著提升光電性能。且使用短鍊配體修飾之元件顯著提升 54 倍光電增益與 58 倍響應度，元件具備較佳之光響應可逆性。本研究成功結合流道化學系統與短鍊表面配體修飾，合成具高效率發光、優異電荷傳輸及長期穩定性之 CsPbI3 PeQDs 設計策略。於材料穩定性與電性之間取得良好平衡，顯著提升其於 LED 背光、Micro-LED 顯示及光電偵測器之應用潛力，為高性能鈣鈦礦量子點光電材料之開發提供重要方向。

All-inorganic CsPbI3 perovskite quantum dots (PeQDs) are promising for optoelectronic applications due to their high photoluminescence quantum yield (PLQY), narrow emission bandwidth, and tunable bandgap. However, their practical use is limited by the trade-off between surface passivation and charge transport, as conventional long-chain ligands provide stability but hinder carrier coupling. This work presents a synergistic strategy combining a fluidic chemistry synthesis with benzothiazole-based short-chain ligand engineering to simultaneously enhance optical efficiency, carrier transport, and stability. The flow-assisted approach enables precise control over nanocrystal formation, while N, S-containing conjugated ligands effectively passivate surface defects and facilitate electronic coupling. As a result, the synthesized PeQDs exhibit near-unity PLQY (~100%) and excellent long-term environmental stability, retaining up to 98% of their initial PLQY after 70 days under ambient conditions. In display applications, the materials achieve an ultra-wide color gamut of ~148.7% NTSC 1931 in LED backlighting. For Micro-LED color conversion layers (CCLs), the PeQDs demonstrate high patternability with a minimum feature size down to 1.1 μm, highlighting their potential for high-resolution display integration. In photodetectors, ligand-engineered devices show a remarkable 54-fold increase in photogain and 58-fold increase in responsivity, indicating reduced carrier trapping.This work provides a scalable strategy to overcome intrinsic limitations in PeQDs and advances their application in next-generation display and sensing technologies.