University of California

Edith D Bourret-Courchesne

Stephen Edward Derenzo

Gregory A Bizarri

Stephen M Hanrahan

Gautam Gundiah

Mattias K Klintenberg

Ramesh B Borade

Marvin J Weber

Andrew Canning

Yetta D Porter-Chapman

Zewu Yan

Anurag Chaudhry

Jie Wang

Scott Edward Taylor

Anurag Chaudry

Shameka Parms

Latoria K Wiggins

Floyd J James

Jia-Qing Wang, Legal Representative

Ivan V Khodyuk

The present invention provides for a composition comprising an inorganic scintillator comprising an optionally lanthanide-doped cesium barium halide, useful for detecting nuclear material.

Lanthanide doped cesium barium halide scintillators

The present invention provides for a composition comprising an inorganic scintillator comprising an optionally lanthanide-doped barium mixed halide, useful for detecting nuclear material.

Lanthanide doped barium mixed halide scintillators

The present invention provides for a composition comprising an inorganic scintillator comprising a doped halide, useful for detecting nuclear material.

Doped halide scintillators

The present invention provides for a composition comprising an inorganic scintillator comprising an alkali metal hafnate, optionally cerium-doped, having the formula AHfO:Ce; wherein A is an alkali metal having a valence of 1, such as Li or Na; and the molar percent of cerium is 0% to 100%. The alkali metal hafnate are scintillators and produce a bright luminescence upon irradiation by a suitable radiation.

Alkali metal hafnium oxide scintillators

The present invention provides for a composition comprising an inorganic scintillator comprising a gadolinium halide, optionally cerium-doped, having the formula AGdX:Ce; wherein A is nothing, an alkali metal, such as Li or Na, or an alkali earth metal, such as Ba; X is F, Br, Cl, or I; n is an integer from 1 to 2; m is an integer from 4 to 7; and the molar percent of cerium is 0% to 100%. The gadolinium halides or alkali earth metal gadolinium halides are scintillators and produce a bright luminescence upon irradiation by a suitable radiation.

Alkali metal and alkali earth metal gadolinium halide scintillators

The present invention provides for a composition comprising an inorganic scintillator comprising a lanthanide-doped strontium barium mixed halide useful for detecting nuclear material.

Lanthanide doped strontium barium mixed halide scintillators

The present invention provides for a composition comprising an inorganic scintillator comprising an optionally lanthanide-doped strontium-barium, optionally cesium, halide, useful for detecting nuclear material.

Lanthanide doped strontium-barium cesium halide scintillators

The present invention provides for a composition comprising an inorganic scintillator comprising a lanthanide-doped barium phosphorous oxide useful for detecting nuclear material.

Lanthanide doped barium phosphorous oxide scintillators

Herein is described a method for identifying semiconductor radiation detector materials based on the mobility of internally generated electrons and holes. It was designed for the early stages of exploration, when samples are not available as single crystals, but as crystalline powders. Samples are confined under pressure in an electric field and the increase in current resulting from exposure to a high-intensity source of ionization current (e.g.,Co gamma rays) is measured. A pressure cell device is described herein to carry out the method. For known semiconductors, the d.c. ionization current depends on voltage according to the Hecht equation, and for known insulators the d.c. ionization current is below detection limits. This shows that the method can identify semiconductors in spite of significant carrier trapping. Using this method and pressure cell, it was determined that new materials BiOI, PbIF, BiPbOCl, BiPbOBr, BiPbOI, BiGdOCl, PbOI, and PbOIare semiconductors.

Identifying new semiconductor detector materials by D.C. ionization conductivity

Fast, bright inorganic scintillators at room temperature are based on radiative electron-hole recombination in direct-gap semiconductors, e.g. CdS and ZnO. The direct-gap semiconductor is codoped with two different impurity atoms to convert the semiconductor to a fast, high luminosity scintillator. The codopant scheme is based on dopant band to dopant trap recombination. One dopant provides a significant concentration of carriers of one type (electrons or holes) and the other dopant traps carriers of the other type. Examples include CdS:In,Te; CdS:In,Ag; CdS:In,Na; ZnO:Ga,P; ZnO:Ga,N; ZnO:Ga,S; and GaN:Ge,Mg.

Codoped direct-gap semiconductor scintillators

A dramatic reduction of the dislocation density in GaN was obtained by insertion of a single thin interlayer grown at an intermediate temperature (IT-IL) after the growth of an initial grown at high temperature. A description of the growth process is presented with characterization results aimed at understanding the mechanisms of reduction in dislocation density. A large percentage of the threading dislocations present in the first GaN epilayer are found to bend near the interlayer and do not propagate into the top layer which grows at higher temperature in a lateral growth mode. TEM studies show that the mechanisms of dislocation reduction are similar to those described for the epitaxial lateral overgrowth process, however a notable difference is the absence of coalescence boundaries.

Method of growing GaN films with a low density of structural defects using an interlayer

A method for growth of III-V, II-VI and related semiconductor single crystals that suppresses random nucleation and sticking of the semiconductor melt at the crucible walls. Small pieces of an oxide of boron B.sub.x O.sub.y are dispersed throughout the comminuted solid semiconductor charge in the crucible, with the oxide of boron preferably having water content of at least 600 ppm. The crucible temperature is first raised to a temperature greater than the melt temperature T.sub.m1 of the oxide of boron (T.sub.m1 =723.degree. K. for boron oxide B.sub.2 O.sub.3), and the oxide of boron is allowed to melt and form a reasonably uniform liquid layer between the crucible walls and bottom surfaces and the still-solid semiconductor charge. The temperature is then raised to approximately the melt temperature T.sub.m2 of the semiconductor charge material, and crystal growth proceeds by a liquid encapsulated, vertical gradient freeze process. About half of the crystals grown have a dislocation density of less than 1000/cm.sup.2. If the oxide of boron has water content less than 600 ppm, the crucible material should include boron nitride, a layer of the inner surface of the crucible should be oxidized before the oxide of boron in the crucible charge is melted, and the sum of thicknesses of the solid boron oxide layer and liquid boron oxide layer should be at least 50 .mu.m.

Growing community of inventors

Berkeley, CA, United States of America

Edith D Bourret-Courchesne