A paper based, all organic, reference-electrode-free ion sensing platform.

We present a reference-electrode free, all organic K sensitive ion sensing platform fabricated by simplest means on a plain sheet of paper. This platform is based on two identical ion selective electrodes (ISEs) which are assembled by bonding a polymeric ion selective membrane (ISM) directly onto a drop-casted PEDOT:PSS electrode. Taking full advantage of the so called pulsetrode concept, a current pulse is used to measure the concentration of the targeted ion.

Deep blue polymer light emitting diodes based on easy to synthesize, non-aggregating polypyrene.

Thorough analyses of the photo- and devicephysics of poly-7-tert-butyl-1,3-pyrenylene (PPyr) by the means of absorption and photoluminescence emission, time resolved photoluminescence and photoinduced absorption spectroscopy as well as organic light emitting devices (OLEDs) are presented in this contribution. Thereby we find that this novel class of polymers shows deep blue light emission as required for OLEDs and does not exhibit excimer or aggregate emission when processed from solvents with low polarity. Moreover the decay dynamics of the compound is found to be comparable to that of well blue emitting conjugated polymers such as polyfluorene.

Focus Issue: Organic light-emitting diodes-status quo and current developments.

The guest editors introduce the Optics Express Energy Express supplement Focus Issue, "Organic Light-Emitting Diodes," which includes six invited articles addressing the challenges of light outcoupling and light management in OLEDs.