Volume 92, Issue 4, 15 August 2002
Index of content:
92(2002); http://dx.doi.org/10.1063/1.1494841View Description Hide Description
Crystalline siliconmicrocavitiesresonant at 1.1 μm were fabricated by using submicron thick Si membranes from a silicon on insulator substrate. These membranes were composed of a single crystalline Si film layered above and below two thin silicon dioxide layers. The low temperature photoluminescence (PL) of the membranes originated from the electron–hole condensed phase, which is characteristic of ultrapure crystalline silicon. The microcavities are then formed by depositing dielectric mirrors on both sides of the membranes. Optical properties of microcavities are studied by optical transmission and PL spectroscopy. The Si PL spectrum is strongly modified by the cavity: at the resonance the PL linewidth is reduced by a factor 3 and the emission is highly angle dependent.
92(2002); http://dx.doi.org/10.1063/1.1493650View Description Hide Description
We propose to utilize glass plates coated with indiumtin oxide (ITO) as far-infrared dichroic mirrors, e.g., in optoelectronic terahertz spectroscopy for purposes such as electro-optic detection of terahertz radiation or in time-resolved experiments with pump pulses in the visible or near-infrared spectral range and probe pulses at terahertz frequencies. Measurements of the complex reflection and transmission coefficients in the spectral range from 0.1 to 2.8 THz indicate that commercially available ITO glass is suitable for this purpose.
92(2002); http://dx.doi.org/10.1063/1.1494840View Description Hide Description
We report the enhancement of ferroelectric properties in vanadium-doped (BIT) thin filmsdeposited by a sol–gel method. Compared to the undoped BIT, V-doped BIT (BTV) showed higher polarizations and a better fatigue resistance as reported in ceramic systems recently [Noguchi et al., Appl. Phys. Lett. 78, 1903 (2001)]. BTV showed a remanent polarization of 15.9 μC/cm2, higher than the value for BIT, 12.5 μC/cm2. The polarization of the BTV thin filmcapacitor decreased by 19%, while that of the BIT decreased by 23% after the fatigue test with switching cycles.
92(2002); http://dx.doi.org/10.1063/1.1495886View Description Hide Description
Doping is a widely used method to enhance the properties of materials. Despite the recently increased understanding of the mechanisms of chemical erosion by low-energy hydrogen ions, the effect of doping on these types of processes is still not well understood. We study the erosion of Si-doped (0–30 at. %) carbon under 20 eV deuterium irradiation using molecular dynamics simulations. We show that the chemical sputtering of carbon decreases with increasing Si concentration. The reasons for the reduced sputtering yield lie in the longer Si–C interaction lengths and efficient dynamic rebonding of hydrocarbon species.