Abstract: A graphite substrate is processed to have surface unevenness in a range of 1 ?m to 8 ?m. Thereby, a semiconductor film to be laminated on the graphite substrate has a stable film quality, and thus adhesion of the graphite substrate and the semiconductor layer can be enhanced. When an electron blocking layer is interposed between the graphite substrate and the semiconductor layer, the electron blocking layer is thin and thus the surface unevenness of the graphite substrate is transferred onto the electron blocking layer. Consequently, the electron blocking layer also has surface unevenness approximately in such range. Thus, almost the same effect as a configuration in which the semiconductor layer is directly connected to the graphite substrate can be produced.

Abstract: A method of manufacturing a radiation detector, comprising: a charge blocking layer generating step of generating a charge blocking layer on a substrate; a CdTe-layer generating step of generating a CdTe layer so as to cover the charge blocking layer on the substrate, the CdTe layer undergoing heterojunction to the charge blocking layer and being composed of a chlorine-doped polycrystalline film; and a heat treatment step of performing a heat treatment on the substrate having the CdTe layer formed thereon.

Abstract: Although Cl (chlorine) is no longer supplied in the course of a first process in which a detecting layer formed by a polycrystalline film or a polycrystalline lamination film by vapor deposition or sublimation is formed, an additional source (e.g., HCl of Cl-containing gas) other than a source is supplied at the start or in the course of the first process. Thus, the detecting layer as the polycrystalline film or the polycrystalline lamination film of CdTe, ZnTe, or CdZnTe can be doped with Cl uniformly in a thickness direction from the start until the end of the first process in film formation. As a result, uniform crystal particles and uniform detection characteristics can be achieved.

Abstract: A graphite substrate is accommodated into a chamber where vacuum drawing is performed via a pump. Thereafter, carbon is heated under vacuum, whereby impurities in the carbon are evaporated causing the carbon to be purified. The carbon in the graphite substrate is purified, achieving suppression of the impurities as donor/acceptor elements and also metallic elements in the semiconductor layer of 0.1 ppm or less, the impurities being contained in the carbon in the graphite substrate. As a result, occurrence of leak current or an abnormal leak point enables to be suppressed, and thus abnormal crystal growth in the semiconductor layer enables to be suppressed.

Abstract: A method of manufacturing a radiation detector, comprising: a charge blocking layer generating step of generating a charge blocking layer on a substrate; a CdTe-layer generating step of generating a CdTe layer so as to cover the charge blocking layer on the substrate, the CdTe layer undergoing heterojunction to the charge blocking layer and being composed of a chlorine-doped polycrystalline film; and a heat treatment step of performing a heat treatment on the substrate having the CdTe layer formed thereon.

Abstract: According to a radiation detector manufacturing method, a radiation detector and a radiographic apparatus of this invention, Cl-doped CdZnTe is employed for a conversion layer, with Cl concentration set to 1 ppm wt to 3 ppm wt inclusive, and Zn concentration set to 1 mol % to 5 mol % inclusive. This can form the conversion layer optimal for the radiation detector. Consequently, the radiation detector manufacturing method, the radiation detector and the radiographic apparatus can be provided which can protect the defect level of crystal grain boundaries by Cl doping in a proper concentration, and can further maintain integral sensitivity to radiation, while reducing leakage current, by Zn doping in a proper concentration.

Abstract: Although Cl (chlorine) is no longer supplied in the course of a first process in which a detecting layer formed by a polycrystalline film or a polycrystalline lamination film by vapor deposition or sublimation is formed, an additional source (e.g., HCl of Cl-containing gas) other than a source is supplied at the start or in the course of the first process. Thus, the detecting layer as the polycrystalline film or the polycrystalline lamination film of CdTe, ZnTe, or CdZnTe can be doped with Cl uniformly in a thickness direction from the start until the end of the first process in film formation. As a result, uniform crystal particles and uniform detection characteristics can be achieved.

Abstract: A radiation detector of this invention includes a Cl-doped CdTe or Cl-doped CdZnTe polycrystalline semiconductor film in which defect levels in crystal grains are protected. This is obtained by grinding CdTe or CdZnTe crystal doped with Cl, and preparing the polycrystalline semiconductor film again by using its powder as the source. The defect levels of crystal grain boundaries in the polycrystalline semiconductor film are also protected by further doping the polycrystalline semiconductor film prepared again with Cl. These features enable manufacture of the radiation detector which has excellent sensitivity and response to radiation.

Abstract: A graphite substrate is processed to have surface unevenness in a range of 1 ?m to 8 ?m. Thereby, a semiconductor film to be laminated on the graphite substrate has a stable film quality, and thus adhesion of the graphite substrate and the semiconductor layer can be enhanced. When an electron blocking layer is interposed between the graphite substrate and the semiconductor layer, the electron blocking layer is thin and thus the surface unevenness of the graphite substrate is transferred onto the electron blocking layer. Consequently, the electron blocking layer also has surface unevenness approximately in such range. Thus, almost the same effect as a configuration in which the semiconductor layer is directly connected to the graphite substrate can be produced.

Abstract: A drive controller varies a bias voltage applied from a bias supply to a conversion layer based on the presence or absence of binning, that is, for a case of carrying out binning where switching elements are driven on the basis of a plurality of rows at a time by a gate drive circuit, and for a case of carrying out no binning where the switching elements are driven on a row-by-row basis by the gate drive circuit. Therefore, in the case of a fluoroscopic mode for acquiring images with binning, a lowering of a dynamic range can be suppressed. In the case of a radiographic mode with no binning, spatial resolution can be made high. That is, a high dynamic range and high spatial resolution can be optimized according to modes of operation.

Abstract: According to a radiation detector manufacturing method, a radiation detector and a radiographic apparatus of this invention, Cl-doped CdZnTe is employed for a conversion layer, with Cl concentration set to 1 ppm wt to 3 ppm wt inclusive, and Zn concentration set to 1 mol % to 5 mol % inclusive. This can form the conversion layer optimal for the radiation detector. Consequently, the radiation detector manufacturing method, the radiation detector and the radiographic apparatus can be provided which can protect the defect level of crystal grain boundaries by Cl doping in a proper concentration, and can further maintain integral sensitivity to radiation, while reducing leakage current, by Zn doping in a proper concentration.

Abstract: A radiation detector of this invention includes a Cl-doped CdTe or Cl-doped CdZnTe polycrystalline semiconductor film in which defect levels in crystal grains are protected. This is obtained by grinding CdTe or CdZnTe crystal doped with Cl, and preparing the polycrystalline semiconductor film again by using its powder as the source. The defect levels of crystal grain boundaries in the polycrystalline semiconductor film are also protected by further doping the polycrystalline semiconductor film prepared again with Cl. These features enable manufacture of the radiation detector which has excellent sensitivity and response to radiation.

Abstract: A radiographic apparatus obtains lag-free radiation detection signals with lag-behind parts removed from radiation detection signals taken from a flat panel X-ray detector as X rays are emitted from an X-ray tube. The lag-behind parts are removed by a recursive computation on an assumption that the lag-behind part included in each X-ray detection signal is due to an impulse response formed of exponential functions, N in number, with different attenuation time constants. X-ray images are created from the lag-free radiation detection signals.

Abstract: A radiographic apparatus obtains lag-free radiation detection signals with lag-behind parts removed from radiation detection signals taken from a flat panel X-ray detector as X rays are emitted from an X-ray tube. The lag-behind parts are removed by a recursive computation on an assumption that the lag-behind part included in each X-ray detection signal is due to an impulse response formed of exponential functions, N in number, with different attenuation time constants. X-ray images are created from the lag-free radiation detection signals.