GaN Heterostructures as Innovative X-ray Imaging Sensors—Change of Paradigm

Abstract

Direct conversion of X-ray irradiation using a semiconductor material is an emerging technology in medical and material sciences. Existing technologies face problems, such as sensitivity or resilience. Here, we describe a novel class of X-ray sensors based on GaN thin film and GaN/AlGaN high-electron-mobility transistors (HEMTs), a promising enabling technology in the modern world of GaN devices for high power, high temperature, high frequency, optoelectronic, and military/space applications. The GaN/AlGaN HEMT-based X-ray sensors offer superior performance, as evidenced by higher sensitivity due to intensification of electrons in the two-dimensional electron gas (2DEG), by ionizing radiation. This increase in detector sensitivity, by a factor of 104 compared to GaN thin film, now offers the opportunity to reduce health risks associated with the steady increase in CT scans in today’s medicine, and the associated increase in exposure to harmful ionizing radiation, by introducing GaN/AlGaN sensors into X-ray imaging devices, for the benefit of the patient.

Lead‐Free Halide Perovskites for Direct X‐Ray Detectors

“…[ 38 ] Moreover, researchers have revealed the effects of materials and device structures on the key figures‐of‐merit of the detectors, which could provide valuable insights into the device response mechanism. [ 39 , 40 , 41 ] Therefore, it is of great significance to systematically summarize some cutting‐edge research and comb out the guidelines for designing advanced radiation detectors. We find that many reviews focus on the perovskite indirect X‐ray detectors, perovskite single‐crystal X‐ray detectors, and lead halide perovskites X‐ray detectors, et al., [ 42 , 43 , 44 ] but there is a lack of systematic reviews on lead‐free perovskite X‐ray detectors.…”

Structural Study of Nano-Clay and Its Effectiveness in Radiation Protection against X-rays

“…When he observed a glowing fluorescent screen, Roentgen discovered the mysterious penetrating radiation called X-rays [2,3]. Nowadays, X-rays offer wide range of applications covering medical [4], military [5], space [6], security [7], and industrial [8] fields and in scientific research [9,10].…”

Editorial for the Special Issue on Wide Bandgap Based Devices: Design, Fabrication and Applications, Volume II

“…In addition, three papers [ 8 , 9 , 10 ] address GaN and SiC circuital applications in power conditioning systems. One paper deals with GaN LEDs [ 11 ], whereas three contributions [ 12 , 13 , 14 ] are concerned with III-nitride-based devices for sensing applications. Two papers [ 15 , 16 ] cover advanced processing techniques.…”

“…On the sensing application side, AlN is exploited by Chiu et al [ 12 ] to fabricate piezoelectric micromachined ultrasonic transducers that are used to build a high-accuracy time-of-flight ranging system. Nguyen et al [ 13 ] investigate the sensing characteristics of NO 2 gas sensors based on Pd-AlGaN/GaN HEMTs at high temperatures, while Thalhammer et al [ 14 ] describe a novel class of X-ray sensors based on AlGaN/GaN HEMTs offering superior sensitivity and the opportunity for dose reduction in medical applications.…”