Xiaojun Wang

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.

Abstract Enhancing solar energy conversion is imperative and maximizing solar energy capture remains significant. Here, nanotechnology toward engineering hybrid photosystem involving biological photosynthetic chloroplasts and dual‐emissive carbon dots (CDs) is employed for improved photosynthesis by harnessing more effective light. Specifically, the as‐prepared CDs show strong absorption in ultraviolet (UV) light region and exhibit intense blue and red light in water, which exactly match the absorption spectrum of chloroplasts. After coating the CDs on the surface of extracted chloroplasts, the hybrid photosystem produces 2.8 times more adenosine triphosphate (ATP) than chloroplasts themselves in vitro. Moreover, CD‐induced enhancement of photosynthesis in living plant is proved as well, showing a maximum increase of 25% in electron transport rates over the leaves without CDs, demonstrating the effective nanobionics engineering of plant performance in vivo. This is the first report on employing the unique dual‐emission trait of nanoparticles, especially the red emission, to augment photoabsorption of both extracted chloroplasts and intact leaves for enhanced photosynthetic properties. This work provides a promising strategy for engineering biological photosynthetic system with dual‐emissive CDs to enhance solar energy conversion both in vivo and in vitro, and promotes the development in the field of nanobionic.

A benchmark publication, the first edition of the Phosphor Handbook set the standard for references in this field. Completely revised and updated, this second edition explores new and emerging fields such as nanophosphors, nanomaterials, UV phosphors, quantum cutters, plasma display phosphors, sol-gel and other wet phosphor preparation techniques, preparation through combustion, bioluminescence phosphors and devices, and new laser materials such as OLED. It also contains new chapters on the applications of phosphors in solid state lighting, photoionization of luminescent centers in insulating phosphors, and recent developments in halide-based scintillators.The handbook provides a comprehensive description of phosphors with an emphasis on practical phosphors and their uses in various kinds of technological applications. It covers the fundamentals, namely the basic principles of luminescence, the principle phosphor materials, and their optical properties. The authors describe phosphors used in lamps, cathode-ray tubes, x-ray, and ionizing radiation detection. They cover common measurement methodology used to characterize phosphor properties, discuss a number of related items, and conclude with the history of phosphor technology and industry.

We synthesized a series of polycrystalline YbCd2−xZnxSb2 (x=0, 0.4, 0.8, 1, 1.2, 1.6, and 2) samples and measured their thermoelectric properties. Thermoelectric figure of merit ZT at 700K is higher than 1.0 for Cd-rich samples (x=0, 0.4, 0.8, and 1.0) and Zn substitute of Cd in YbCd2Sb2 can easily tune carrier concentration and reduce thermal conductivity. When x=0.4, sample exhibits the highest power factor (12–20μWcm−1K−2), the lowest lattice thermal conductivity (1.0Wm−1K−1 at 300K), highest ZT (1.2 at 700K), and best “self-compatibility.” The first principles calculations were performed to study the influences of bonding and electronic structures on physical properties.