A semiconductor radiation detector capable of measuring a γ-ray energy spectrum at 122 keV and 662 keV and having an energy resolution of no greater than 8 % with respect to 122 keV γ-rays, a nuclear medicine diagnostic device using the detector and a method for producing the semiconductor radiation detector are provided.
A semiconductor radiation detector 101 uses a semiconductor crystal 111 sandwiched by a cathode 112 and an anode 113. The semiconductor crystal 111 is configured from a thallium bromide single crystal in which the concentration of lead as an impurity is less than 0.1 ppm, the full width at half maximum of the (110) rocking curve in the X-ray diffraction in specimen tilting angle scan is no greater than 1.6 degrees, the full width at half maximum in specimen in-plane rotation angle scan is no greater than 3.5 degrees, and the full width at half maximum in X-ray incident angle scan is no greater than 1.3 degrees.