Wide Band THz Detectors Based on HgCdTe Epitaxial Films

It has been widely accepted that wide-band-gap semiconductor SiC can provide low-loss semiconductor switches and diodes for the power electronics applications. The SiC devices enable the low-loss and compact converters and inverters.

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Growth of amorphous and epitaxial ZnSiP2–Si alloys on Si

Journal of Materials Chemistry C ◽

10.1039/c7tc05545e ◽

2018 ◽

Vol 6 (11) ◽

pp. 2696-2703 ◽

Cited By ~ 10

Author(s):

Aaron D. Martinez ◽

Elisa M. Miller ◽

Andrew G. Norman ◽

Rekha R. Schnepf ◽

Noemi Leick ◽

...

Keyword(s):

Band Gap ◽

Wide Band ◽

Epitaxial Films ◽

Wide Band Gap ◽

Lattice Matched

ZnSiP2 is a wide band gap material lattice matched with Si, with potential for Si-based optoelectronics. Here, amorphous ZnSiP2–Si alloys are grown with tunable composition. Films with Si-rich compositions can be crystallized into epitaxial films.

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Seven-colour photometry at the Geneva Observatory

Symposium - International Astronomical Union ◽

10.1017/s0074180900053535 ◽

1966 ◽

Vol 24 ◽

pp. 262-266 ◽

Cited By ~ 1

Author(s):

M. Golay

Keyword(s):

Wide Band ◽

Electric System ◽

Band Type

During the last 5 years, we have developed a seven-colour photometry at the Geneva Observatory. Our multicolour photo-electric system is of a wide-band type; the bandwidth being about 500Å for four filters. The three others are similar to theUBVsystem. In Table 1 we give the filter combinations used in our photometry (1).

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TEM and cathodoluminescence of precipitates in II-VI semiconductors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104509 ◽

1988 ◽

Vol 46 ◽

pp. 488-489

Author(s):

Joanna L. Batstone

Keyword(s):

Crystal Growth ◽

Band Gap ◽

Local Strain ◽

Wide Band ◽

Optoelectronic Device ◽

Wide Band Gap ◽

Bulk Crystal Growth ◽

Transmission Electron ◽

Device Applications ◽

Stoichiometry Control

Interest in II-VI semiconductors centres around optoelectronic device applications. The wide band gap II-VI semiconductors such as ZnS, ZnSe and ZnTe have been used in lasers and electroluminescent displays yielding room temperature blue luminescence. The narrow gap II-VI semiconductors such as CdTe and HgxCd1-x Te are currently used for infrared detectors, where the band gap can be varied continuously by changing the alloy composition x.Two major sources of precipitation can be identified in II-VI materials; (i) dopant introduction leading to local variations in concentration and subsequent precipitation and (ii) Te precipitation in ZnTe, CdTe and HgCdTe due to native point defects which arise from problems associated with stoichiometry control during crystal growth. Precipitation is observed in both bulk crystal growth and epitaxial growth and is frequently associated with segregation and precipitation at dislocations and grain boundaries. Precipitation has been observed using transmission electron microscopy (TEM) which is sensitive to local strain fields around inclusions.

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Precipitation in Al + 4% Cu Epitaxial Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100101670 ◽

1968 ◽

Vol 26 ◽

pp. 384-385

Author(s):

S. Herd ◽

S. M. Mader

Keyword(s):

Solid Solution ◽

Bulk Material ◽

Epitaxial Films ◽

Detectable Change ◽

Cu Films ◽

Solution Treated ◽

Single Crystal Films ◽

Crystal Films ◽

Diffraction Patterns ◽

Deposited Films

Single crystal films in (001) orientation, about 1500 Å thick, were produced by R-F sputtering of Al + 4 wt % Cu onto cleaved KCl at 150°C substrate temperature. The as-deposited films contained numerous θ-CuAl2 particles (C16 structure) about 0.1μ in size. They were transferred onto Mo screens, solution treated and rapidly cooled (within about ½ min) so as to retain a homogeneous solid solution. Subsequently, the films were aged in vacuum at various temperatures in order to induce precipitation and to compare structures and morphologies of precipitate particles in Al-Cu films with those found in age hardened bulk material.Aging for 3 weeks at 60°C or 48 hrs at 100°C did not produce any detectable change in high resolution micrographs or diffraction patterns. In this range Guinier-Preston zones (GP) form in quenched bulk material. The absence of GP in the present experiments in this aging range is perhaps due to the cooling rate employed, which might be more equivalent to an aged and reverted bulk material than to a quenched one.

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Epitaxial growth manner and structure of superconducting oxide films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173145 ◽

1990 ◽

Vol 48 (4) ◽

pp. 2-3

Author(s):

Yoshichika Bando ◽

Takahito Terashima ◽

Kenji Iijima ◽

Kazunuki Yamamoto ◽

Kazuto Hirata ◽

...

Keyword(s):

Ultrathin Films ◽

Film Surface ◽

High Energy ◽

Epitaxial Films ◽

Layer By Layer ◽

Initial Growth ◽

In Situ Growth ◽

High Quality ◽

Activated Reactive Evaporation

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.

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Electron microscopic characterization of diamond thin films and substrates for diamond heteroepitaxial growth

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100154937 ◽

1989 ◽

Vol 47 ◽

pp. 592-593

Author(s):

J.B. Posthill ◽

R.P. Burns ◽

R.A. Rudder ◽

Y.H. Lee ◽

R.J. Markunas ◽

...

Keyword(s):

Thin Films ◽

Wide Band ◽

Deposition Process ◽

Heteroepitaxial Growth ◽

Electron Microscopic ◽

Wide Band Gap ◽

Lattice Matching ◽

Different Types ◽

Diamond Thin Films

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.

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