Johannes Kepler University of Linz

About: Johannes Kepler University of Linz is a education organization based out in Linz, Oberösterreich, Austria. It is known for research contribution in the topics: Computer science & Thin film. The organization has 6605 authors who have published 19243 publications receiving 385667 citations.

Excitation-power dependence of the near-band-edge photoluminescence of semiconductors.

Abstract: We present a model calculation for the dependence of the near-band-edge photoluminescence (NBEPL) on the power of the exciting laser light. Our model explains all features of the NBEPL power dependence that were previously observed in experiment: (i) the variation of the excitonic photoluminescence intensity I with ${\mathit{L}}^{\mathit{k}}$, where L is the excitation power and k is an exponent between 1 and 2, (ii) deviations from the I\ensuremath{\sim}${\mathit{L}}^{\mathit{k}}$ law as L is varied by more than two orders of magnitude, and (iii) the variation of k for exciton emission lines when the wavelength of the exciting laser radiation is varied. Furthermore, our model relates the k values of the free exciton, bound exciton, and the free-to-bound transitions. The results are in excellent agreement with experimental data.

Organic Nonvolatile Memory Transistors for Flexible Sensor Arrays

Abstract: Using organic transistors with a floating gate embedded in hybrid dielectrics that comprise a 2-nanometer-thick molecular self-assembled monolayer and a 4-nanometer-thick plasma-grown metal oxide, we have realized nonvolatile memory arrays on flexible plastic substrates. The small thickness of the dielectrics allows very small program and erase voltages (≤6 volts) to produce a large, nonvolatile, reversible threshold-voltage shift. The transistors endure more than 1000 program and erase cycles, which is within two orders of magnitude of silicon-based floating-gate transistors widely employed in flash memory. By integrating a flexible array of organic floating-gate transistors with a pressure-sensitive rubber sheet, we have realized a sensor matrix that detects the spatial distribution of applied mechanical pressure and stores the analog sensor input as a two-dimensional image over long periods of time.