Accession Number : AD0771526

Title :   Semiconductor Neutron Detectors.

Descriptive Note : Final technical rept. 13 Mar 72-12 Jan 73,


Personal Author(s) : Wald,F. ; Bullitt,J.

Report Date : JAN 1973

Pagination or Media Count : 36

Abstract : The goal of this program was the crystal growth of red alpha-rhombohedral boron for use as a semiconductor neutron detector. Red boron was prepared as microscopic crystals by a variety of techniques. Crystals of red boron 0.1 mm long were prepared by the chemical vapor deposition (CVD) of BBr3 at 1170C. Microscopic crystals of red boron could also be prepared by the vapor-liquid-solid and traveling solvent method variations of CVD as well as by precipitation from copper-gold solutions. Solid solutions of copper and gold in beta-rhombohedral boron have been grown by the traveling heater method from a copper-gold alloy at temperatures of 1000 to 1200C. The electrical and optical properties of this material appear to be dominated by the same kind of trapping mechanism that controls the properties of high purity beta-boron. The only distinguishing feature of this material seems to be that both the trap concentration and the free carrier concentration are quite high. The free carrier mobilities of this material are low, which precludes its use for semiconductor radiation detection. (Author)

Descriptors :   *Neutron detectors, *Semiconductor devices, *Boron, *Crystal growth, Solid solutions, Vapor deposition, Optical properties, Electrical properties

Subject Categories : Nuclear Instrumentation

Distribution Statement : APPROVED FOR PUBLIC RELEASE