Hard X-ray detection using a single 100 nm diameter nanowire

Area of Science:

• Materials Science
• Nanotechnology
• Medical Imaging

Background:

• Submicron sensors are crucial for advancing X-ray imaging and diffraction resolution.
• Current limitations in sensor technology hinder progress in materials science and medicine.

Purpose of the Study:

• To present electrical measurements of a single Indium Phosphide (InP) nanowire transistor under hard X-ray exposure.
• To investigate the X-ray induced conductance and carrier lifetimes in nanoscale sensors.
• To demonstrate the potential of nanowire transistors for high-resolution X-ray imaging.

Main Methods:

• Fabrication and electrical characterization of a 100 nm diameter InP nanowire transistor.
• Exposure of the nanowire transistor to hard X-rays.
• Time-resolved conductance measurements to determine carrier lifetimes.
• Direct imaging of an X-ray nanofocus using the nanowire sensor.

Main Results:

• Observed X-ray induced conductance exceeding expected values by over 5 orders of magnitude.
• Measured characteristic carrier lifetimes on the order of seconds, attributed to long-lived traps.
• Demonstrated a strong amplification effect due to these long-lived traps.
• Achieved submicron resolution in direct imaging of an X-ray nanofocus.

Conclusions:

• Single InP nanowire transistors exhibit significant X-ray induced signal amplification.
• Long-lived traps play a key role in the enhanced sensitivity of these nanoscale sensors.
• Nanowire transistors offer a promising pathway to achieving higher resolution in X-ray applications.