The formation of pure single crystalline silicon nanoparticles by microwave induced decomposition of silane in a low pressure flow reactor is reported. The morphology and crystal structure of the particles are characterized in situ by particle mass spectrometry (PMS) and ex situ by means of X-ray diffraction, high resolution transmission electron microscopy, electron energy loss spectroscopy, and infrared spectroscopy. The preparation method allows for the adjustment of the mean particle diameter in the range 6 nm < or = dPM < or = 11 nm by controlling the precursor concentration, gas pressure, and microwave power. Spectroscopic investigations reveal that the particles are single crystal silicon. The potential on n- or p-type doping is in progress.

No abstract

No abstract

No abstract

The formation of iron particles without and with carbon coating was studied in a hot wall flow reactor. The precursors ironpentacarbonyl (IPC, Fe(CO)5) and ethylene (C2H4) both diluted in N2 were used in a concentric tubular flow arrangement and were heated to temperatures between 570 and 1170 K at pressures between 50 and 500 mbar. In experiments without C2H4, either individual iron particles in the size range of or long iron chains composed of several hundreds of individual iron particles were found depending on the reaction conditions. In experiments with C2H4 addition, these particles or particle chains were covered by a thin carbon/carbide layer. The size of the primary particles was measured in situ by time-resolved laser-induced incandescence (TR-LII) and ex situ by rapid thermophoretic particle probing and TEM imaging.

No abstract

Nanocrystalline gamma-Fe2O3 particles were produced in a microwave flow reactor. The reaction of iron pentacarbonyl [Fe(CO)5] with the plasma gases Ar/O2 to form nanosized particles was followed by in situ particle mass spectrometry. The particle mass spectrometer combines a nonintrusive sampling technique with a calibration-free mass determination. The influence of process parameters like microwave power, precursor concentration, and pressure on the particle size was studied. The results reveal a mean particle diameter in the range of 4-5 nm with a slight dependence on the process parameter. The geometric standard deviation of the measured size distribution was always between 1.1 and 1.2.

In this work, we describe the developments behind our "Brite3" generation rigid OLED lighting panels as well as bendable panels based on thin glass. We developed high brightness white OLEDs with excellent performance based on the stacking approach, achieving 80-90 lm/W on rigid panels and 60 lm/W on bendable panels.