Two from one: It is possible to form two different, interpenetrating polymer structures—silicon dioxide and a phenolic resin—simultaneously in a single step without the formation of by‐products by using a readily polymerizable, organic silicon spiro compound. This new polymerization process enables the fabrication of materials with domain sizes of 0.5 to 3 nm.

The efficiency roll-off at high brightness levels is a key factor limiting the application of organic light emitting diodes. We investigate triplet-triplet annihilation in an archetype phosphorescent host-guest system. We show that the currently used host-guest systems are not at the physical limit set by intrinsic annihilation, but have an increased roll-off due to aggregate formation. The existence of these aggregates is directly proven by transmission electron microscopy.

Aus eins mach zwei: Ausgehend von einer leicht polymerisierbaren Silicium‐Spiroverbindung gelingt es, in einem einzelnen Prozessschritt zwei interpenetrierende Polymerstrukturen – SiO2 und Phenolharz – ohne die Bildung von Beiprodukten herzustellen. Diese neue Polymerisationsmethode ist auf verschiedenste Monomere anwendbar und macht Polymermaterialien mit Domänengrößen von 0.5 bis 3 nm zugänglich.

We have presented systematic cross-plane thermal conductivity (λ) data for the undoped strain-symmetrized Si/Ge superlattices grown on Si(111) with superlattice (SL) period thickness varying from 3.6 to 16 nm. In thin SL period (L⩽7 nm) samples, the data have shown considerable reductions of λ, by more than 50% and 30% compared to the SiGe alloy and to the earlier reported values in (100)-oriented Si/Ge superlattice structures (SLS), respectively. For the thick SL period samples (L>10 nm), λ has shown a tendency to saturate at the SiGe alloy value. This is understood as, with increasing L, the SLS breaks and the SiGe alloying starts to grow. This structural behavior is clearly observed in the cross-plane transmission electron microscope images as well. In addition to these, for the thin SL period (L⩽7 nm) samples, the data have shown a shallow minimum which is attributed to the competing behavior of the wave nature and the classical particle nature of the localized phonons. Nevertheless, the present study of thermal conductivity on undoped strain-symmetrized Si/Ge SLs in (111) orientation suggests that an enhancement of thermoelectric figure-of-merit Z is possible.

Using aberration-corrected scanning transmission electron microscope and energy dispersive x-ray spectroscopy, single, isolated impurity atoms of silicon and platinum in monolayer and multilayer graphene are identified. Simultaneously acquired electron energy loss spectra confirm the elemental identification. Contamination difficulties are overcome by employing near-UHV sample conditions. Signal intensities agree within a factor of two with standardless estimates.