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

Area of Science:

• Semiconductor physics
• Medical imaging technology
• Materials science

Background:

• Direct X-ray conversion using semiconductors is an emerging field.
• Current X-ray detector technologies face limitations in sensitivity and resilience.
• Gallium Nitride (GaN) devices are crucial for high-power, high-frequency, and optoelectronic applications.

Purpose of the Study:

• To introduce a novel class of X-ray sensors based on GaN thin film and GaN/AlGaN high-electron-mobility transistors (HEMTs).
• To demonstrate the superior performance of GaN/AlGaN HEMT-based X-ray sensors compared to existing technologies.
• To explore the potential of these sensors in reducing health risks associated with medical X-ray imaging.

Main Methods:

• Fabrication of X-ray sensors utilizing GaN thin film.
• Integration of GaN/AlGaN high-electron-mobility transistors (HEMTs) for enhanced electron intensification.
• Characterization of sensor performance under X-ray irradiation, focusing on sensitivity.

Main Results:

• GaN/AlGaN HEMT-based sensors exhibit significantly higher sensitivity.
• Sensitivity enhancement is attributed to the intensification of electrons in the two-dimensional electron gas (2DEG) under ionizing radiation.
• Achieved a sensitivity increase of approximately 10⁴ times compared to GaN thin film sensors.

Conclusions:

• GaN/AlGaN HEMT-based X-ray sensors represent a promising advancement in detector technology.
• The enhanced sensitivity offers a pathway to reduce radiation dose for patients undergoing CT scans.
• This technology has the potential to improve patient safety in medical X-ray imaging.