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Silk is a natural biocompatible material that can be integrated in a variety of photonic systems and optoelectronic devices. The silk replication of patterned substrates with features down to tens of nanometers is exploited to realize highly transparent, mechanically stable, and free-standing structures with optical wavelength size. We demonstrate organic lasing from a blue-emitting stilbene-doped silk film spin-coated onto a one-dimensional distributed feedback grating (DFB). The lasing threshold is lower than that of organic DFB lasers based on the same active dye. These findings pave the way to the development of an optically active biocompatible technological platform based on silk. [ABSTRACT FROM AUTHOR]

AlInN/AlN/GaN heterostructures were characterized by atomic force microscopy. V-defects and channels were observed. In phase-contrast mode, these features were found related to inhomogeneities associated with In-segregation (and/or In-diffusion) and Al-rich surface reconstruction. The electrical characterization via conductive atomic force microscopy showed enhanced conductivity regions related to In-rich traces within channels and V-defects. [ABSTRACT FROM AUTHOR]

In this work the authors report on photocurrent spectroscopy analyses on pentacene thin film transistors that have been bias stressed and exposed to atmosphere over a long period of time (up to 80 days). They have studied the charge transport properties and the electronic excited state energy and distribution of these organic thin film devices. They also have identified the major excitonic and band gap transition energies and have investigated their quite different behavior following exposure to atmosphere or to bias stress. Different charge carrier distributions and trapping phenomena are proposed to describe the observed effects. [ABSTRACT FROM AUTHOR]