基于量子棒纳米纤维大面积定向排列的偏振增亮膜及其在宽色域显示中的应用

作为一种新兴的纳米材料,CdSe/CdS量子棒的偏振发光特性使其在应用于新型液晶显示中极具潜力,而如何将量子棒材料在宏观尺度上大面积的定向排列是实现该技术的关键性问题。在本文中,我们报道了一种大面积、含定向排列量子棒、基于PMMA纳米纤维制成的偏振增亮膜。首先,采用一种新的TBP辅助合成方法,合成出具有核壳结构的CdSe/CdS量子棒。该材料的绝对量子产率达到了60%,发光波长的半峰宽为25nm,具有182nm的大Stokes位移。随后将这些量子棒溶于氯仿、DMF和PMMA混合溶液中制备用于静电纺丝的纺丝液。通过静电纺丝技术,将含有量子棒的聚合物纳米纤维通过滚筒收集处理,得到了一张透明、大面积、偏振增强的增亮膜,5cm~2增亮膜的偏振度为0.45。最后将制备的增亮膜嵌入一个液晶显示模组中测试,结果显示该模组的亮度提高了18.4%。这一结果表明我们制备的量子棒增亮膜在新型宽色域高光效显示领域具有非常广阔的应用前景。

Large-scale active luminance film with enhanced polarization made of aligned quantum-rod-containing polymeric nanofibers for highly efficient and wide color gamut LCD displays

CdSe/CdS quantum rods (QRs) with polarized light emission have great potential in the next generation liquid crystal displays (LCD) backlight. Aligning these QRs in large scale is the key for practical applications. In this paper, we report a large scale film made of aligned QRs in PMMA fibers. Making use of a new tributylphosphine (TBP)-assisted synthetic method, we firstly synthesized uniform CdSe/CdS QRs with high absolute quantum yield (QY) of 60%, narrow full width at half maximum (FWHM) of 25 nm and large Stokes shift of 182 nm. Then, these oil phase CdSe/CdS QRs (maintaining the high absolute QY) dissolved in the mixed solution of chloroform, dimethylformamide (DMF) and polymethyl methacrylate (PMMA) were used to electrospin aligned QR-containing PMMA nanofibers. Collecting these fibers by a roller, we were able to make large-scale active luminance film with enhanced polarization with these PMMA nanofibers aligned. For a 5 cm² size film, the polarization was measured to be 0.45. The film was further inserted into a mobile LCD for test and the brightness of LCD was enhanced by 18.4% with the film. Our results indicate that our aligned film is a very promising backlight solution for highly efficient and wide color gamut LCD displays.