QUANTUM RODS AND THEIR FUNCTIONAL FILMS FOR DISPLAY

Presently, liquid crystal display (LCD) and organic light emitting diode (OLED) are two popular display technologies. However, LCD technology has small color gamut and low power conversion efficiency, and OLEDs are suffering color shifting and cannot achieve wide color gamut display, because emission is not narrow enough and intrinsic organic materials are unstable.

Semiconductor quantum dots (QDs) are nanomaterials with high absolute quantum yield (QY) and has size dependent optical properties and narrow emission as well as they can achieve wide color gamut display. As a variant of QDs, quantum rods (QRs) reserve all these advantages, and have polarized emission and suffer less reabsorption of light. Therefore, QRs are brought into focus and applied in display techniques to achieve polarized display, high power conversion efficiency and wide color gamut.

In this thesis, detailed investigations on the synthesis, display applications of QR materials are carried out. Firstly, CdSe/CdS dot-in-rod QRs with high absolute photoluminescent QY and accurate controllable morphology are synthesized. Secondly, the synthesized QRs are aligned to fabricate QR enhancement films with high degree of linearly polarized emission, which can improve efficiency and color gamut of LCD technique. Thirdly, the chiral transferred QRs are dopped into self-assembled chiral supramolecular system to fabricate circularly polarized luminescent films. Finally, the synthesized QRs are used as emissive layer of OLEDs and achieve wider color gamut and high external quantum efficiency. This research work shows that QRs are promising candidates for display applications.

液晶显示(LCD)和有机发光二极管(OLED)是目前主流的两种显示技术。然而，LCD存在色域小、功率转换效率低等问题；OLED由于有机材料固有的不稳定和发射光不够窄的原因，导致无法实现宽色域，且存在颜色漂移等问题。

半导体量子点(QDs)是一种具有高绝对量子产率(QY)的纳米材料，具有随尺寸变化的光学性质和窄发射光谱，可实现宽色域显示。作为量子点的一种变体，量子棒(QRs)保留了所有这些优点，且具有偏振发射和较少的光重吸收等特性。因此，将QRs引起广泛关注并被应用于显示技术中，以实现偏振显示、高功率转换效率和宽色域等功能。

本文对QR材料的合成、显示领域的应用等方面进行了详细的研究。首先，合成了具有高光致发光绝对量子产率和精确可控形貌的点状核心棒状壳层的CdSe/CdS QRs；其次，将合成的QRs进行排列，制备出高度线偏振发射的QR增强薄膜，应用并提高了液晶显示技术的效率和色域。再次，将手性转移的QRs掺杂到自组装的手性超分子体系中，制备了圆偏振发光的QR薄膜。最后，将合成的QRs作为OLED器件的发光层，实现了器件更宽的色域和更高的外量子效率。这项研究工作表明，QRs码具有很好的显示应用前景。

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