Compositions – Inorganic luminescent compositions – Zinc or cadmium containing
Reexamination Certificate
2006-05-23
2006-05-23
Koslow, C. Melissa (Department: 1755)
Compositions
Inorganic luminescent compositions
Zinc or cadmium containing
C252S30140R, C252S30160S, C252S30140H, C257S043000, C257S087000, C257S086000, C257S076000
Reexamination Certificate
active
07048872
ABSTRACT:
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.
REFERENCES:
patent: 3027329 (1962-03-01), Grimmeiss et al.
patent: 3534211 (1970-10-01), Lehmann
patent: 3602753 (1971-08-01), Evans et al.
patent: 5976412 (1999-11-01), Itoh et al.
patent: 6140669 (2000-10-01), Lozykowski et al.
patent: 6674098 (2004-01-01), Niki et al.
patent: 6815736 (2004-11-01), Mascarenhas
patent: WO 01/08229 (2001-02-01), None
W. Lehman, entitled: “Edge Emission ofn-Type Conducting ZnO and CdS”,Solid-State Electronics,Pergamon Press 1966, vol. 9, pp. 1107-1110.
W. Lehman, entitled: “Optical Absorption Edges of ZnO and CdS”,Journal of the Electrochemical Society,Nov. 1965, vol. 112, No. 11, pp. 1150-1151.
D. Luckey, entitled “A Fast Inorganic Scintillator”,Nuclear Instruments and Methods,vol. 62 (1968), 119-120.
Ruiping Wang and Arthur W. Sleight, entitled: “High Conductivity in Gallium-Doped Zinc Oxide Powders”,Chem. Mater.,1996, vol. 8, 433-439.
K. Thonke et al., entitled: “Donor-acceptor pair transitions in ZnO substrate material”,Physica B,308-310 (2001) 945-948.
S. B. Zhang et al., entitled: “Intrinsicn-type versusp-type doping asymmetry and the defect physics of ZnO”,Physical Review B,vol. 63, 075205.
P. J. Simpson et al., entitled “Superfast timing performance from ZnO scintillators”,Nuclear Instruments and Methods in Physics Research A,vol. 505 (2003), 82-84.
Bourret-Courchesne Edith
Derenzo Stephen E.
Klintenberg Mattias K.
Weber Marvin J.
Koslow C. Melissa
Lawrence Berkeley National Laboratory
Milner Joseph R.
The Regents of the University of California
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