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US 5,512,756 AGranted
X-ray detector with direct conversion
AssigneeSiemens Aktiengesellschaft
InventorsEberhard Bayer, deceased, Andreas Jahnke, Eric Chemisky, Ralf-Dieter Schnell
Life of this patent
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Abstract
An x-ray detector element suitable for use in computer tomography has a semi-insulating semiconductor body composed of a compound semiconductor, and is operated with a constant voltage source so that it functions as an x-ray-sensitive photoconductor. A measurement instrument is connected across the voltage source for detecting the photocurrent, which is indicative of the x-rays incident on the semiconductor body.
Claims10
An x-ray detector comprising:
- a photoconductor formed by a lamina having a crystalline, semi-insulating semiconductor body having high purity in its interior, said semiconductor body being formed of material selected from the group consisting of GaAs, CdTe, CdSe, HgTe, Culn.sub.x Ga.sub.1-x Se.sub.2-2y S.sub.2y, wherein 1.gtoreq.x and y.gtoreq.0, said semiconductor body having opposite surfaces;
- electrodes respectively disposed on said opposite surfaces of said semiconductor body and defining an input surface for x-rays, said input surface being substantially perpendicular to said opposite surfaces;
- said semiconductor body having a flat, highly doped layer region immediately beneath the electrode at each of said opposite surfaces;
- a capacitor;
- a constant voltage source electrically connected in parallel with said capacitor and connected to said electrodes for charging said electrodes with a constant voltage and producing a substantially uniform electric field throughout said semiconductor body between said electrodes;
- and
- measuring means for detecting a photocurrent flowing through said photoconductor as a result of x-rays incident on said input surface of said photoconductor.
4 more elements
A method for detecting x-rays comprising the steps of:
- producing a laminar, crystalline, semi-insulating semiconductor body with high purity in its interior having opposite surfaces and selecting material for said semiconductor body from the group consisting of GaAs, CdTe, CdSe, HgTe, Culn.sub.x Ga.sub.1-x Se.sub.2-2y S.sub.2y, wherein 1.gtoreq.x and y.gtoreq.0;
- producing a flat, highly doped layer region on each of said opposite surfaces of said semiconductor body;
- disposing an electrode on each of said opposite surfaces of said semiconductor body directly covering said highly doped layer region to form a photoconductor;
- orienting said photoconductor with said electrodes substantially parallel to incoming x-rays;
- charging said electrodes with a constant voltage in a range between 8 and 30 volts, and producing a substantially uniform electric field throughout said semiconductor body between said electrodes, said photoconductor thereby generating a photocurrent as a result of x-rays incident thereon;
- connecting a measurement device for said photocurrent in parallel with said photoconductor and capacitively coupling said measuring device to said photoconductor;
- and
- measuring said photocurrent with said measuring device.
5 more elements
Dependencies are inferred from the claim text.