Research in organic electronics has included advances in materials, devices, and processes. Device architectures, increasingly complex circuitry, reliable fabrication methods, and new semiconductors are enabling the incorporation of organic electronic components in products including OLED displays and flexible electronic paper.

Pentacene-based thin-film integrated circuits patterned only with polymeric shadow masks and powered by near-field coupling at radio frequencies of 125 kHz and above 6 MHz have been demonstrated. Sufficient amplitude modulation of the rf field was obtained to externally detect a clock signal generated by the integrated circuit. The circuits operate without the use of a diode rectification stage. This demonstration provides the basis for more sophisticated low-cost rf transponder circuitry using organic semiconductors.

We report here methods of surface modification and device construction which consistently result in lab-scale pentacene-based TFTs with mobilities at or above 5 cm2/Vs. Surface modifications include polymeric ultrathin films presenting a passivated interface on which the semiconductor can grow. High performance TFTs have been fabricated on a variety of dielectric materials, both organic and inorganic, and are currently being implemented in manufacturable constructions. Our surface modifications have also proven useful for substituted pentacene materials and for a variety of other organic semiconductors. In addition, we report an all organic active layer, rf-powered integrated circuit. Further experiments and statistical analyses are underway to explain the elevated mobility in our samples, and efforts have been made to confirm these results through collaboration.

Blue-green (λ=511 nm) separate confinement laser structures based on lattice-matched MgZnSSe-ZnSSe-CdZnSe have been grown by molecular beam epitaxy. Wide stripe gain-guided devices have been fabricated from several such wafers. These devices exhibit room-temperature pulsed threshold current densities as low as 630 A/cm2 and threshold voltages less than 9 V. Using a novel self-aligned process that results in a planar surface, buried-ridge laser diodes have also been fabricated. These devices have demonstrated room-temperature threshold currents as low as 2.5 mA, which is more than a factor of 50 lower than that of any previously reported II-VI laser diode. Room-temperature operation at duty factors up to 50% has been demonstrated. The far-field patterns from these devices indicate single lateral mode operation, suitable for diffraction-limited applications, such as optical data storage.

Deep level transient spectroscopy (DLTS) has been used to investigate trap levels in sol-gel derived polycrystalline Pb(Zr0.54,Ti0.46)O3 thin films. Metal-ferroelectric-metal capacitor structures 2400 and 3000 Å in thickness were fabricated and characterized using a constant voltage DLTS system. Prominent peaks associated with a single trap level were observed in all samples studied. The activation energy was determined to be 267 meV from DLTS spectra Arrhenius plots. Infrared transmission characterization was performed on PbTiO3 thin films also prepared using sol-gel synthesis. A loss in the transmission at 270±12 meV was observed which we attribute to hole emission from the same trap detected using DLTS.