Internal Compensation X-Ray Detector Pixel Circuit with IGZO TFT and Perovskite Single Crystal

Abstract

The flat panel detector (FPD) detecting X-ray has several applications like medical imaging, security checks, and industrial inspection. Nowadays, an active pixel sensor (APS) is applied for X-ray detectors composed of three transistors normally. One is for reset of the circuit and the other two are for amplification and readout. This fundamental structure offers advantages in terms of high resolution, rapid detection speed, and heightened sensitivity. However, the output signal is reliant on electrical parameters, particularly the threshold voltage and mobility of the amplifying transistor, which can vary for various reasons. To mitigate this variability, compensation methods, both internal and external, have been explored. In this research, we introduce an innovative internal compensation pixel circuit tailored for X-ray detectors and validate its performance through simulations based on amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs). The simulation results indicate that our proposed pixel circuit demonstrates remarkable resilience, with only a -0.16% and 0.04% error rate when threshold voltage variation falls within the range of ±0.5 V, in contrast to the 10% variation observed in conventional pixel circuits.