Completed Projects
Completed Projects
Embedded Files
- Purification and Growth InI and InI X Tl 1-X Crystals for Nuclear Detection Applications (link JCG paper)
Supported by US Department of Energy, DoE
June 1st 2010 to October 30 2015Supported by US Department of Energy, DoE
Investigators
Investigators
Principal Investigator: Prof. A.G Ostrogorsky · Illinois Institute of Technology · E-mail: AOstrogo@IIT.edu
Co-Investigators
Prof Arnold Burger · Fisk University · Center for Photonic Materials and Devices · E-mail: aburger@fisk.edu
Indium Iodide Single Crystals grown using Vertical Bridgman (top) and Czochralski (bottom) Processes
Summary
Summary
Wide energy gap semiconductors have superior energy resolution, and hold the promise for room temperature gamma-ray spectrometers. So far, most of the effort has been placed on growing CdZnTe (CZT) crystals which are expensive and have materials limitations.
In our previous projects at RPI and Fisk University, we considered a number of promising heavy metal halides 1 , 2 . Our conclusion was that InI is the most promising heavy metal halide. The key advantages of InI compared to CZT are:
InI has energy gap Eg=2.0 eV is above that of CZT
InI’s density (5.31 g/cm 3 ) is solid, although is somewhat lower than density of CZT
InI is not toxic
InI has a relatively low melting point, 365 °C, and does not react or stick to silica
InI can be prepared using melt growth techniques
InI is a simple stable binary. Compared to CZT, it is easy to grow from the melt since there is no problems related to compositional segregation and phase separation, and post growth annealing is not needed
InI is not hydroscopic, and is insoluble in water, methanol, acetone
Crystal growth experiments were conducted primarily at Prof. Ostrogorsky's laboratory, at Illinois Institute of Technology (IIT). Characterization and device fabrication was conducted at Prof Arnold's laboratory at Fisk University.
2. B6P Semiconductor Crystals for Neutron Detection
2. B6P Semiconductor Crystals for Neutron Detection
Sponsored by DHS, DNDO Office
2012 to 2015Sponsored by DHS, DNDO Office
Investigators
Investigators
Principal Investigator: Prof. A.G Ostrogorsky · Illinois Institute of Technology · E-mail: AOstrogo@IIT.edu
Summary
Summary
B-10 has a high thermal neutron absorption cross section (3800 barns) which makes B-10 based crystals very good candidate for semiconductor neutron detectors. B 6 P is III-V compound semiconductor having energy band gap of 3.3 eV, The conventional III-V compounds, which are BN, BP, BAs, are too difficult to grow as macroscopic crystals, and have only marginally useful electric properties. Review of the current literature and co-PIs previous research [1] indicates that B6P can be grown from the melt under moderate gas pressures, and can be made with high electrical resistivity, and high optical transparency.
Attempting to grow BP6 from melt
3. SUBSA Investigation
3. SUBSA Investigation
Supported by NASA CASIS
Supported by NASA CASIS
Astronaut Dr. Peggy Whitson conducting first experiment in MSG (bottom left) and The monitoring Room at Rensselaer Polytechnic Institute (RPI) (bottom right)
Summary
Summary
SUBSA (Solidification Using a Baffle in Sealed Ampoules) was the first investigation conducted in. the Microgravity Science Glovebox (MSG) at the International Space Station (ISS).
On June 5 2002, Space Shuttle Endeavour carried the Crew of the Expedition 5, the MSG and the SUBSA hardware to the ISS ( utilization flight UF2-STS-111, (LINK). The key goal of the investigation was to reduce convection (with or without the baffle) to the point that it does not interfere with dopant transport in the melt, so that reproducible data, i.e., diffusion-controlled initial transient and steady state segregation are obtained.
Ten experiments were planned for. Seven experiments were conducted, four Te-doped InSb and three Zn-doped InSb, see [] and [] respectively.
Fig. to the left shows the astronaut Dr. Peggy Whitson conducting the first experiment in MSG, on July 11, 2002 and the monitoring room at Rensselaer Polytechnic Institute (RPI).
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