A Perovskite-Graphene Device for X-ray Detection.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Semiconductor Devices

Background:

• Graphene field-effect transistors (GFETs) offer unique electronic properties.
• Perovskite materials are emerging as sensitive optoelectronic materials.
• X-ray detection technologies are crucial for medical imaging and scientific research.

Purpose of the Study:

• To investigate the performance of a perovskite-based graphene field-effect transistor (P-GFET) for X-ray detection.
• To evaluate the sensitivity and responsivity of the P-GFET across various X-ray parameters.
• To assess the feasibility of P-GFETs as low-energy X-ray photon detectors.

Main Methods:

• Fabrication of P-GFETs by spin-coating methylammonium lead iodide (MAPbI3) perovskite onto GFET chips.
• Irradiation of devices using a molybdenum target X-ray tube with controlled voltage and current.
• Dose measurements using ion-chamber and thermo-luminescent dosimeters.
• GEANT4 and MCNP simulations for dose rate and incident power determination.

Main Results:

• Sensitivity showed a strong positive correlation with source-drain voltage.
• Sensitivity decreased exponentially with increasing X-ray tube current and energy.
• Similar trends were observed for responsivity.
• The P-GFET demonstrated feasibility for detecting low-energy X-rays (< 70 keV).

Conclusions:

• P-GFETs are viable candidates for low-energy X-ray detection.
• Device performance is tunable via source-drain voltage and X-ray parameters.
• Further research can optimize P-GFETs for advanced X-ray sensing applications.