Ž . Ž . The growth of cubic aluminum nitride AlN and cubic gallium nitride GaN is studied. The effects of ambient pressure and substrate temperature on the structure of the AlN and GaN films are systematically investigated. It is shown that the films are amorphous when the temperature and the pressure are too low. Cubic AlN is obtained at a temperature of 8008C and a pressure of 0.2 Torr. Cubic...

Piezoelectric aluminum nitride thin films were deposited on aluminum-molybdenum (AlMo) metallic nanocomposites using reactive DC sputtering at room temperature. The effect of sputtering parameters on film properties was assessed. A comparative study between AlN grown on AlMo and pure aluminum showed an equivalent (002) crystallographic texture. The piezoelectric coefficients were measured to be...

An Aluminum Nitride (AlN) MEMS resonator technology has been developed, enabling massively parallel filter and oscillator arrays on a single chip. Low loss filter banks and resonator arrays covering the 10MHz10GHz frequency range have been demonstrated, as has monolithic integration with inductors and CMOS circuitry. The high level of integration enables miniature multi-band, spectrally-aware a...

Air-coupled piezoelectric micromachined ultrasound transducer arrays, operating at ~190 kHz, have been fabricated utilizing an aluminum nitride piezoelectric layer. Improved fabrication processes have reduced the frequency variation seen in our previous work with single transducers resulting in arrays of transducers with resonant frequencies (fn) that match within the fractional half-power band...

The electronic properties of heterojunction electron gases formed in GaN/AlGaN core/shell nanowires with hexagonal and triangular cross sections are studied theoretically. We show that at nanoscale dimensions, the nonpolar hexagonal system exhibits degenerate quasi-one-dimensional electron gases at the hexagon corners, which transition to a core-centered electron gas at lower doping. In contras...

Numerous technical advances in the area of polymer light emitting diodes (PLEDs) have been made since their discovery in 1990 by Friend et al at Cambridge University . PLEDs are derivatives from the more commonly known LED (light emitting diode) devices. LEDs are solid-state semiconductor devices that convert electrical energy into light. They are typically used as indicator lights and numeric ...