AlSb photonic detectors for gamma-ray spectroscopy. Progress report, October 1994--August 1995

Technical Report · Sun Dec 31 04:00:00 EST 1995

DOI:https://doi.org/10.2172/188646· OSTI ID:188646

Becla, P; Witt, A F

Aluminum antimony (AlSb) is an indirect band gap semiconductor with Eg of about 1.62 eV at 300 K and about 1.75 eV at 77 K. This material, is extremely difficult to obtain in single crystal form because of the very high reactivity of aluminum with oxygen, and the high volatility of antimony. Moreover, molten AlSb reacts with nearly all crucible materials available. Since Welker`s first attempts in 1952, only very few different experimental approaches have been used to grow single crystals of AlSb, e.g. by Bridgman, Czochralski and MBE. All experimental results, however, indicate that many of the properties of AlSb, e.g. carrier concentration, electron-hole mobility and carrier life-time, differ significantly from the theoretically predicted values. The main objective of this research period has been to develop a method leading to improved crystallographic and electronic quality of AlSb crystals, making them more suitable for device applications. The research program was aimed along the following two directions: (1) study the growth of AlSb via Bridgman, Czochralski and THM techniques; (2) comprehensive characterization of grown material, related to the use of compounds for high energy gamma detectors. Variables in the growth study were growth temperature, equilibrium pressure, growth rate, doping, crucible material, seeding and encapsulation. The characterization study included crystallographic quality (grain size, etch pits, precipitates, inclusions), electronic quality (conductivity type, carrier concentration and mobility), optical properties (spectral absorption, photoconductivity, persistent absorption) and others (SIMS, EPR).

• Research Organization: Massachusetts Inst. of Tech., Cambridge, MA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: FG08-94NV11627
• OSTI ID: 188646
• Report Number(s): DOE/NV/11627--T1; ON: DE96005162
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
ALUMINIUM ALLOYS
ANTIMONY ALLOYS
BRIDGMAN METHOD
CRYSTAL GROWTH
CZOCHRALSKI METHOD
ENERGY GAP
EXPERIMENTAL DATA
GAMMA SPECTROMETERS
MICROSTRUCTURE
PHYSICAL PROPERTIES
PROGRESS REPORT
RESEARCH PROGRAMS
SEMICONDUCTOR MATERIALS