Research in the use of organic polymers as the active semiconductors in light-emitting diodes has advanced rapidly, and prototype devices now meet realistic specifications for applications. These achievements have provided insight into many aspects of the background science, from design and synthesis of materials, through materials fabrication issues, to the semiconductor physics of these polymers.

Electroluminescence in conjugated polymers

Lithium-ion batteries have had a profound impact on our daily life, but inherent limitations make it difficult for Li-ion chemistries to meet the growing demands for portable electronics, electric vehicles and grid-scale energy storage. Therefore, chemistries beyond Li-ion are currently being investigated and need to be made viable for commercial applications. The use of metallic Li is one of the most favoured choices for next-generation Li batteries, especially Li-S and Li-air systems. After falling into oblivion for several decades because of safety concerns, metallic Li is now ready for a revival, thanks to the development of investigative tools and nanotechnology-based solutions. In this Review, we first summarize the current understanding on Li anodes, then highlight the recent key progress in materials design and advanced characterization techniques, and finally discuss the opportunities and possible directions for future development of Li anodes in applications.

Reviving the lithium metal anode for high-energy batteries

The organization of behavior: A neuropsychological theory

A review was presented to demonstrate a historical description of the synthesis of light-emitting conjugated polymers for applications in electroluminescent devices. Electroluminescence (EL) was first reported in poly(para-phenylene vinylene) (PPV) in 1990 and researchers continued to make significant efforts to develop conjugated materials as the active units in light-emitting devices (LED) to be used in display applications. Conjugated oligomers were used as luminescent materials and as models for conjugated polymers in the review. Oligomers were used to demonstrate a structure and property relationship to determine a key polymer property or to demonstrate a technique that was to be applied to polymers. The review focused on demonstrating the way polymer structures were made and the way their properties were controlled by intelligent and rational and synthetic design.

Synthesis of Light-Emitting Conjugated Polymers for Applications in Electroluminescent Devices

Electron and ambipolar transport in organic field-effect transistors.

Charge injection and recombination at the metal–organic interface

Colorfast Blue‐Light‐Emitting Random Copolymers Derived from Di‐n‐hexylfluorene and Anthracene

Today's technologies for storing data have vexing limitations: Dynamic random access memory chips only retain data for short times, hard disk drives are slow relative to processor speed, and "flash" memory (like that in digital cameras) is expensive. Researchers are thus searching for a fast, inexpensive memory technology that retains data even when the power is off. As [Scott][1] discusses in his Perspective, the search has identified several interesting avenues that are being actively pursued. But the real-world challenges are severe, and proponents of nonvolatile memory need to take a hard look at the practical realities before declaring success.

 [1]: http://www.sciencemag.org/cgi/content/full/304/5667/62

https://science.sciencemag.org/content/sci/304/5667/62.full.pdf

Is There an Immortal Memory

In organic thin film transistors (OTFTs), charge transport occurs in the first few monolayers of the semiconductor near the semiconductor/dielectric interface. Previous work has investigated the roles of dielectric surface energy, roughness, and chemical functionality on performance. However, large discrepancies in performance, even with apparently identical surface treatments,indicate that additionalsurface parametersmust beidentified and controlled in order to optimize OTFTs. Here, a crystalline, dense octadecylsilane (OTS) surface modification layer is found that promotes twodimensional semiconductor growth. Higher mobility is consistently achieved for films deposited on crystalline OTS compared to on disordered OTS, with mobilities as high as 5.3 and 2.3cm 2 V � 1 s � 1 for C60 and pentacene, respectively. This is a significant step toward morphological control of organic semiconductors which is directly linked to their thin film charge carrier transport.

The Role of OTS Density on Pentacene and C60 Nucleation, Thin Film Growth, and Transistor Performance

Measurements of charge injection from indium tin oxide (ITO) into the organic semiconductor, tetraphenyl diamine doped polycarbonate (PC:TPD), were carried out. The current injected at the contact was measured as a function of the hole mobility in the organic semiconductor, which was varied from 10(-6) to 10(-3) cm (2)/V x s by adjusting the concentration of the hole transport agent, TPD, in the PC host. These experiments reveal that the current injected at the contact is proportional to the hole mobility in the bulk. As a result, the ITO/PC:TPD contact is found to limit current flow in all samples, regardless of the hole mobility in PC:TPD.

J. Campbell Scott

Papers

Charge injection and recombination at the metal–organic interface

Colorfast Blue‐Light‐Emitting Random Copolymers Derived from Di‐n‐hexylfluorene and Anthracene

Is There an Immortal Memory

The Role of OTS Density on Pentacene and C60 Nucleation, Thin Film Growth, and Transistor Performance

Mobility-Dependent Charge Injection into an Organic Semiconductor