Performance Evaluation of AgBi2I7 Based Direct Conversion X-ray Detector

Abstract

In the field of medical diagnosis, x-ray imaging is one of the most significant branches. Presently, highly researched halide based perovskites can be interesting candidates for x-ray detection. However, the presence of toxic lead in halide based perovskites has made a surge in research to enhance the x-ray performance of image detectors using a variety of possible photoconductors. This paper demonstrates the x-ray imaging performance of AgBi2I7 rudorffite single crystal. The maximum sensitivity of AgBi2I7 has been found to be 312.53 μCGyair ⁻¹cm⁻² with an optimum thickness of 0.08 mm under an electric field of 2.00 V/mm for mammography. For chest radiography, a sensitivity of 2870.61 μCGyair ⁻¹cm⁻² with an optimum thickness of 0.28 mm under an electric field of 2.00 V/mm has been found. Furthermore, the AgBi2I7 detector with a photoconductor thickness of 1 mm, under a low applied electric field of 0.38 V/mm shows a charge collection and absorption-limited sensitivity of 158.88 μCGyair ⁻¹cm⁻² and a sensitivity of 282.87 μCGyair ⁻¹cm⁻² from the slope of the photocurrent density versus dose rate characteristics. Our theoretical analysis suggests AgBi2I7 rudorffite single crystal can replace presently mainstreamed amorphous selenium (a-Se) in diagnostic x-ray imaging.