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More information on the used QDs; Color spectrum; Color conversion efficiency; Comparisons and advantages.

Stable electroluminescence from micro-pixelated light-emitting diode (μLED) occurs when electrons and holes are continuously injected from external electrodes. Different from the general recognition, in this work, μLED works in an operation mode, namely, non-electrical contact and non-carrier injection mode, and can be ‘wirelessly’ lit up without external charge injection, which is different from the general recognition. Inherent holes and electrons in μLEDs can provide sufficient carriers for radiative recombination under alternating-current electric field. A possible model related to the diffusion of majority carrier and the drift of minority carrier in μLED was proposed, which is further confirmed by the employment of a ‘carrier pump’. Finally, the intrinsic characteristics of the device-in-capacitor, namely, self-protection against electrical breakdown, were discussed. This work demonstrates a new device configuration and an alternative operating mode for μLED and provides a research manner to obtain advanced μLED-based technology.

This manuscript reports the impact of fullerene structure on the morphology and miscibility of small molecules via a fullerene bulk heterojunction solar cell. The small angle neutron scattering and neutron reflectometry measurements were analyzed to provide quantifiable measures of the morphology of the resultant mixtures, offering miscibility, domain sizes, interfacial area between the small molecule and fullerene, and depth profiles in the mixtures. These results indicate that the bis-adduct fullerenes exhibit lower miscibility in small molecules. Correlation of miscibility and morphology to photovoltaic properties indicates that small molecule/fullerene miscibility is crucial to rationally optimize the design of fullerenes for use in small molecule organic photovoltaics. A higher open circuit voltage was obtained for bis-adduct fullerene devices which, however, does not translate to an increased power conversion efficiency. This decrease in performance is associated with the lower miscibility of bis-fu...

Printed electronics is a rapidly developing field of research which covers any electronic devices or circuits that can be processed using direct printing techniques. Among those printing techniques, inkjet printing is a technique of increasing interest for organic field-effect transistors (FETs) due to its fully data driven and direct patterning. In this work, the morphology of semi-conducting polymer/insulating polymer blends from inkjet printing and their FET properties have been investigated. We attempted to optimize the morphology of the blends by the addition of a co-solvent to the blend solution prior to film deposition. By varying the boiling temperature of the co-solvent, blend films are fabricated with varying domain purity and different degree of semi-conducting polymer ordering. The morphologies of all the as-cast samples from inkjet printing and subsequently thermally annealed samples are characterized by grazing incidence wide angle x-ray scattering and small angle neutron scattering. The results indicate that the sample where a low boiling temperature co-solvent is used exhibits a lower degree of semi-conducting polymer ordering and less pure domains, resulting in a decrease of hole mobility. The morphologies that are formed when high boiling temperature co-solvent is used, however, give a higher degree of semi-conducting polymer ordering along with higher domain purity, significantly improving hole mobility up to 1.44 cm2 V−1 s−1 at VDS = 40 V. More importantly, with thermal annealing, all the samples exhibit similar semi-conducting polymer ordering and domain sizes while the domain purity significantly varies. This work is a unique example that demonstrates the importance of domain purity in the optimization of morphology and FET performance, which is previous unavailable. It also provides a novel process that can efficiently control the morphology of semi-conducting polymer/insulating polymer mixtures during deposition to maximize FET performance from inkjet printing. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 1760–1766