Nanosecond Pulse Generation in a Silicon Microwire

We report the generation of trapezoidal current pulses by applying a dc voltage to a single nanocrystalline silicon microwire through a load. The wire is expected to be physically disconnecting and reconnecting at a constriction near its midpoint as a result of volume change in repeated solid-liquid phase transitions. A scanning electron microscope image and the wire's electrical characteristics suggest that the wire is partially molten at the time of disconnection. The current pulses rise from 0 to 7 mA and have widths of 13.48 ± 0.65 ns, a repetition rate of 9.12 ± 0.06 MHz, rise/fall times ≤ 350 ps, a peak power density of ~1.9 kW/mm
²
, and a very consistent pulse shape.