Fig. 1: Physical design and fabrication of the VFG CsPbBr3 detector.
a Scheme of the VFG detector. The Ga-In alloy (EGI) was used as the anode, and Au was used as the cathode in the VFG detector. b Simulated two-dimensional distribution of the weighting potential of the Au cathode with detector dimensions of 4.5 × 4.5 × 10 mm3 according to the Shockley–Ramo theorem, the observation plane was in the middle of the side. c–h CsPbBr3 single crystals and as-fabricated VFG detectors with various dimensions of 4.0 × 4.0 × 10.2 mm3, 5.0 × 7.0 × 17.3 mm3 and 6.5 × 7.0 × 22.1 mm3. i Absorption characteristics of CsPbBr3 crystal with thicknesses ranging from 1 to 30 mm for high energy photons. j–l Gamma ray spectroscopic response of the 10.2 mm (detector I), 17.3 mm (detector II) and 22.1 mm (detector III) thick VFG detectors under an uncollimated 137Cs source, respectively. The applied voltages were 1050 V, 3400 V, and 1700 V, respectively. m Linearity response of detector I under uncollimated 57Co and 137Cs source simultaneously. n Summary of the energy resolution achieved by perovskite semiconductors for 137Cs 662 keV gamma ray source. CsPbBr3 grown by melt method: 12.85%54, 9.91%55, 3.8%20, 2.0%56, 1.8%16, 1.4%16, 1.4%16; CsPbBr3 grown by solution method: 12.20%57, 11.47%58, 11%59, 7.31%60, 7.20%61, 5.5%62,63; hybrid perovskites by solution method: 6.7%64, 6.5%34, 5.9%65, 2.9%17, 1.7%66.
