Results of rapid (laser induced) and slow (heating stage induced) crystallization studies on Te1−xGex, 0≤x≤0.6, are reported. The time it takes to laser crystallize varies with x by more than four orders of magnitude. Films with stoichiometric compositions, Te and GeTe, can be crystallized using laser pulses of less than 100 ns duration. Unlike Te, which spontaneously crystallizes at room temperature, GeTe has a crystallization temperature of >150 °C. From these results we argue that, in general, compound materials allow realization of fast-switching, reversible, phase-change optical recording media. Furthermore, this fast-switching capability, from the amorphous to the crystalline state and back, can be attained simultaneously with long term data (amorphous phase) stability, provided the melting temperature of the compound is sufficiently high.

With the continued proliferation of display intensive applications for portable electronics devices, the need for lower power, higher image quality video displays has never been greater. Pixtronix is uniquely able to meet these requirements through its MEMS (micro-electo-mechanical system) display technology, which enables the development of direct view displays with breakthrough optical transmission over 60%, color gamut over 100% (of NTSC, CIE 1931), 1,000:1 contrast ratio and wide view angles.

We present data on a new erasable phase change medium, demonstrating for the first time that very short erase times can be obtained without sacrificing room-temperature stability of the amorphous state. Thin films of the composition Sb2Se underwent 10% relative reflectivity changes when switched with a laser between amorphous and crystalline states. Twenty milliwatt, 50 ns laser pulses were used for writing amorphous spots; 6.9 mW, 200 ns pulses were used for erasing. A playback carrier to noise ratio of 43 dB was observed on a plastic disk. Amorphous spots could be heated in a microscope to 175 °C before they crystallized. Transmission electron microscopy and x-ray diffraction indicate that the erased state is single phase and polycrystalline. The crystal structure, however, does not correspond to known compounds in the antimony-selenium system.

The Pixtronix DMS™ (Digital Micro Shutter) display technology intrinsically provides exceptional image quality due to its optical architecture and device technology. This technology, based on MEMS micro‐shutters formed on active TFT backplanes, has enabled the development of color sequential, time division gray scale, direct‐view displays achieving breakthrough performance ‐ including 150% NTSC (CIE 1976 u'v' color space) color gamut, 24‐bit color, > 500:1 contrast ratio and 170° viewing angle, all at 1/4 the power consumption of comparable TFT‐LCD display modules. In addition to this, these displays present horizontal contrast viewing angle comparable to that of OLEDs providing exceptional color saturation in large angle viewing directions. This paper will briefly describe the Pixtronix DMS™ display technology. It will also describe key display architecture elements of DMS technology responsible for the excellent optical performance. The optical characterization of prototype displays and discussion of the results will be presented. A non‐emissive technology like DMS technology is able to provide performance close to that of emissive technologies like OLED at a power much lower than that of an LCD display.

Articles you may be interested inKinetics of crystal nucleation in undercooled droplets of Sb-and Te-based alloys used for phase change recording J. Appl. Phys. 98, 054910 (2005); Effect of multilayer structure and laser pulse width on the reversible cycling of phase change optical storage media