Zinc oxide nanostructures and high electron mobility nanocomposite thin film transistors

This paper reports on the synthesis of zinc oxide (ZnO) nanostructures and examines the performance of nanocomposite thin-film transistors (TFTs) fabricated using ZnO dispersed in both n- and p-type polymer host matrices. The ZnO nanostructures considered here comprise nanowires and tetrapods and were synthesized using vapor phase deposition techniques involving the carbothermal reduction of solid-phase zinc-containing compounds. Measurement results of nanocomposite TFTs based on dispersion of ZnO nanorods in an n-type organic semiconductor ([6, 6]-phenyl-C61-butyric acid methyl ester) show electron field-effect mobilities in the range 0.3-0.6 cm2V-1 s-1. representing an approximate enhancement by as much as a factor of 40 from the pristine state. The on/off current ratio of the nanocomposite TFTs approach 106 at saturation with off-currents on the order of 10 pA. The results presented here, although preliminary, show a highly promising enhancement for realization of high-performance solution-processable n-type organic TFTs. © 2008 IEEE.

Integrated optically triggered polarisation-switching in InGaAsP twin-stripe injection lasers

A new form of ultrafast bistable polarization switching in twin-stripe injection lasers has been observed. For the first time, triggering between bistable states has been achieved by injecting light from a neighboring laser integrated on the same chip. Ultrafast switching times of 250 ps have been measured (detector limited).

Optically triggered polarisation bistability in GaInAsP twin stripe injection lasers using integrated devices

A bistable polarization switching element and optical triggering source has been produced by etching a facet in a twin stripe semiconductor laser. The switching element is formed by a pair of stripe segments at one end of the device and triggered with short light pulses from the other two segments. Detector limited switching risetimes have been measured at 250 ps.

高速液体撞击下固体材料内的应力波传播

用速度为450m/s的水射流对具有复杂表面形状的有机玻璃材料进行了冲击实验，试验表面有转角、台阶、缺口、斜坡等，用偏振光光学系统和高速摄影机，观察了固体内应力波的反射、干涉、衍射等传播行为。在进行高速摄影时，采用了每秒10~6幅和每秒5x10~5幅的摄影速度，用速度为850m/s的水射流，试验了侧向射流对有机玻璃板的冲击破坏力。实验发现，固体内的应力波及其传播行为不但与固体的几何形状有关，而且与液体接触固体表面时的状态有关。实验证明，侧向射流具有足够的破坏力，虽然其头部可能是由小尺寸的雾滴组成。实验结果将有助于进一步详细分析在高速液／固撞击时材料的动态受力状态。