Two of the recent major research topics in optoelectronic devices are discussed: the development of new organic materials (both molecular and polymeric) for the active layer of organic optoelectronic devices (particularly organic light-emitting diodes (OLEDs)), and light management, including light extraction for OLEDs and light trapping for organic solar cells (OSCs). In the first section, recent developments of phosphorescent transition metal complexes for OLEDs in the past 3-4 years are reviewed. The discussion is focused on the development of metal complexes based on iridium, platinum, and a few other transition metals. In the second part, different light-management strategies in the design of OLEDs with improved light extraction, and of OSCs with improved light trapping is discussed.

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The alkyne moieties of poly(3-hexylthienyleneethynylene) were reacted with tetracyanoethylene or 7,7,8,8-tetracyanoquinodimethane by microwave irradiation to produce donoracceptor chromophores in the polymer main chain. The resulting polymers were fully characterized by GPC, 1 H NMR, and IR spectroscopies, and elemental analyses. They were both thermally and chemically stable, as revealed by thermogravimetric analyses and ESR measurements. UV-vis-NIR spectroscopy revealed charge-transfer bands in the low-energy region, and electrochemistry confirmed the narrower band gaps with the elevated HOMO and lower LUMO levels relative to the precursor polymer. To take advantage of these postfunctionalization methods, p-type doping of the polymers with I 2 was attempted. Room temperature conductivities of the postfunctionalized polymers reached 4.5 Â 10 À5 S cm À1 , which was about 10 times greater than that of the precursor polymer.

In order to determine a material's hydrogen storage potential, capacity measurements must be robust, reproducible, and accurate. Commonly, research reports focus on the gravimetric capacity, and often times the volumetric capacity is not reported. Determining volumetric capacities is not as straight‐forward, especially for amorphous materials. This is the first study to compare measurement reproducibility across laboratories for excess and total volumetric hydrogen sorption capacities based on the packing volume. The use of consistent measurement protocols, common analysis, and figure of merits for reporting data in this study, enable the comparison of the results for two different materials. Importantly, the results show good agreement for excess gravimetric capacities amongst the laboratories. Irreproducibility for excess and total volumetric capacities is attributed to real differences in the measured packing volume of the material.

Platinum(II) polyyne polymers containing thiophene-acceptor-thiophene units are synthesized, and their main chain alkynes are functionalized by the formal cycloaddition-retroelectrocyclization reaction with tetracyanoethylene (TCNE). The polymer energy levels are signifi cantly decreased by the TCNE addition. Bulk-heterojunction solar cells are fabricated using the TCNE-adducted platinum(II) polyyne polymers. The use of these polymers as p-type semiconductors in combination with n-type fullerene derivatives indicates that the p-type semiconducting ability decreases by approximately fi ve to ten times after the TCNE addition. On the contrary, when the TCNE-adducted polymers are employed as a substitute for the fullerene derivatives, the all-polymer solar cells are initially fabricated.alternating conjugated polymers possessing both narrow band gaps and crystallinity in the thin fi lm states. For example, it was found that 2,7-carbazole-based and benzodithiophene-based donor-acceptor conjugated polymers are excellent p-type semiconductors with a suffi cient chemical stability compared with the fl uorene-based counter polymers, [ 2 ] and the optimized PCE is approaching 10%. [ 3 ] Recently, platinum(II) polyyne polymers have also attracted increasing interest as p-type semiconductors, and various types of donor-acceptor units have been examined for expansion of the absorption range. [ 4 ] All-polymer solar cells is another approach, which is mainly based on the development of novel n-type semiconducting polymers. The advantages of n-type polymer semiconductors over the conventional fullerene derivatives include expanded light absorption, tailor-made energy levels through chemical synthesis, and an excellent fi lm coating ability due to polymer blends. The pioneering work by Friend and co-workers [ 5 ] employed cyanated poly( p -phenylenevinylene) as an n-type poly mer, and the mixed fi lm with a p-type polythiophene derivative realized the photocurrent generation with a PCE of 1.9%. Recently, perylene diimide-based polymers and fl uorene-based polymers containing benzodithiadiazole IPCE Wavelength (nm) All-polymer solar cells