Flexible composite film with artificial opal photonic crystals for efficient all-day passive radiative cooling.

All-day passive radiative cooling has recently attracted broader attention for its potential as a viable energy technology. Although tremendous progress has been achieved, the design and fabrication of low-cost high-efficiency radiators for all-day passive radiative cooling remains a challenge. Herein, we report a new type of flexible composite radiator film with built-in artificial opal-like structures for all-day passive radiative cooling.

Highly linearly polarized light emission from flexible organic light-emitting devices capitalized on integrated ultrathin metal-dielectric nanograting.

Although there have been tremendous achievements ever since the first work on an organic electroluminescent (EL) device that emitted polarized light, the development of flexible polarized emission organic light-emitting devices (OLEDs) is not without hurdles, and the challenge towards real-world applications still requires tremendous effort. In this paper, we proposed highly linearly polarized light-emission from flexible green OLEDs capitalized on integrated ultrathin metal-dielectric nanograting. The acquired polarized device with meticulously optimized geometric parameters yields an angle-invariant average extinction ratio beyond 20.

Laser speckle formed disordered micro-meander structures for light extraction enhancement of flexible organic light-emitting diodes.

A new approach for efficiently recovering the wasted light energy in conventional flexible organic light-emitting diodes (FOLEDs) is developed by implementing disordered micro-meander structures (DMMs) via laser speckle holography technology. Compared to conventional flat device architecture, the structured FOLEDs with DMMs result in substantial improvement of the device efficiency and superior angular color stability. The resulting current efficiency (CE) and external quantum efficiency (EQE) are 1.

Two novel blue phosphorescent host materials containing phenothiazine-5,5-dioxide structure derivatives.

Two novel D-A bipolar blue phosphorescent host materials based on phenothiazine-5,5-dioxide: 3-(9-carbazol-9-yl)-10-ethyl-10-phenothiazine-5,5-dioxide (CEPDO) and 10-butyl-3-(9-carbazol-9-yl)-10-phenothiazine-5,5-dioxide (CBPDO) were synthesized and characterized. The photophysical, electrochemical and thermal properties were systematically investigated. CEPDO and CBPDO not only have a high triplet energy but also show a bipolar behavior.

Charge transport dependent high open circuit voltage tandem organic photovoltaic cells with low temperature deposited HATCN-based charge recombination layers.

Mechanisms of charge transport between the interconnector and its neighboring layers in tandem organic photovoltaic cells have been systematically investigated by studying electronic properties of the involving interfaces with photoelectron spectroscopies and performance of the corresponding devices. The results show that charge recombination occurs at HATCN and its neighboring hole transport layers which can be deposited at low temperature. The hole transport layer plays an equal role to the interconnector itself.

Controlling charge injection properties in polymer field-effect transistors by incorporation of solution processed molybdenum trioxide.

A simply and facilely synthesized MoO3 solution was developed to fabricate charge injection layers for improving the charge-injection properties in p-type organic field-effect transistors (OFETs). By dissolving MoO3 powder in ammonium (NH3) solvent under an air atmosphere, an intermediate ammonium molybdate ((NH4)2MoO4) precursor is made stable, transparent and spin-coated to form the MoO3 interfacial layers, the thickness and morphology of which can be well-controlled. When the MoO3 layer was applied to OFETs with a cost-effective molybdenum (Mo) electrode, the field-effect mobility (μFET) was significantly improved to 0.