Imaging performance of a CaWO4/CMOS sensor

Abstract

The aim of this study was to investigate the modulation transfer function (MTF) and the effective gain transfer function (eGTF) of a nondestructive testing (NDT)/industrial inspection complementary metal oxide semiconductor (CMOS) sensor in conjunction with a thin calcium tungstate (CaWO 4) screen. Thin screen samples, with dimensions of 2.7x3.6 cm 2 and thickness of 118.9 μm, estimated from scanning electron microscopy-SEM images, were extracted from an Agfa Curix universal screen and coupled to the active area of an active pixel (APS) CMOS sensor. MTF was assessed using the slanted-edge method, following the IEC 62220-1-1:2015 method. MTF values were found high across the examined spatial frequency range. eGTF was found maximum when CaWO 4 was combined with charge-coupled devices (CCD) of broadband anti-reflection (AR) coating (17.52 at 0 cycles/mm). The combination of the thin CaWO4 screen with the CMOS sensor provided very promising image resolution and adequate efficiency properties, thus could be also considered for use in CMOS based X-ray imaging devices, for various applications.

Energy‐Band Engineering by Remote Doping of Self‐Assembled Monolayers Leads to High‐Performance IGZO/p‐Si Heterostructure Photodetectors

“…With the advances in emerging technology for image analysis in fields such as autonomous driving, [ 1 ] artificial intelligence, [ 2 ] medical imaging, [ 3 ] and augmented reality, [ 4 ] development of high‐resolution image sensors has attracted a lot of attention in order to transmit accurate color information. To implement high‐performance photodetectors that meet the performance requirements of the abovementioned applications, research efforts are accelerating on the utilization of emerging semiconductor materials (such as metal oxides, [ 5 ] transition metal dichalcogenides, [ 6 ] perovskites, [ 7 ] and other organic materials [ 8 ] ) accompanied by nanotechnology.…”