State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China.
State Key Laboratory of Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China.
Adv Mater. 2018 Mar;30(13):e1705948. doi: 10.1002/adma.201705948. Epub 2018 Feb 12.
Circularly polarized light (CPL) is central to photonic technologies. A key challenge lies in developing a general route for generation of CPL with tailored chiroptical activity using low-cost raw materials suitable for scale-up. This study presents that cellulose films with photonic bandgaps (PBG) and left-handed helical sense have an intrinsic ability for circular polarization leading to PBG-based CPL with extraordinary |g | values, well-defiend handedness, and tailorable wavelength by the PBG change. Using such cellulose films, incident light ranging from near-UV to near-IR can be transformed to passive L-CPL and R-CPL with viewing-side-dependent handedness and |g | values up to 0.87, and spontaneous emission transformed to R-CPL emission with |g | values up to 0.68. Unprecedented evidence is presented with theoretical underpinning that the PBG effect can stimulate the R-CPL emission. The potential of cellulose-based CPL films for polarization-based encryption is illustrated. The evaporation-induced self-assembly coupled with nanoscale mesogens of cellulose nanocrystals opens new venues for technological advances and enables a versatile strategy for rational design and scalable manufacturing of organic and inorganic CPL films for photonic applications.
圆偏振光（CPL）是光子技术的核心。一个关键的挑战在于开发一种通用的方法，使用低成本的原材料来产生具有定制手性活性的 CPL，这些原材料适合规模化生产。本研究表明，具有光子带隙（PBG）和左手螺旋结构的纤维素薄膜具有内在的圆偏振能力，从而导致基于 PBG 的 CPL 具有非凡的 |g| 值、明确的手性和可通过 PBG 变化来调整的波长。使用这种纤维素薄膜，从近紫外到近红外的入射光可以被转化为具有侧视依赖性手性和高达 0.87 的 |g| 值的被动 L-CPL 和 R-CPL，自发发射可以被转化为高达 0.68 的 R-CPL 发射。本研究提供了前所未有的证据和理论支持，表明 PBG 效应可以刺激 R-CPL 发射。纤维素基 CPL 薄膜在偏振加密方面的应用潜力也得到了说明。纤维素纳米晶体的蒸发诱导自组装与纳米级介晶相结合，为技术进步开辟了新的途径，并为有机和无机 CPL 薄膜在光子学应用中的合理设计和规模化制造提供了一种通用策略。
