Enhanced X-ray Sensitivity of MAPbBr₃ Detector by Tailoring the Interface-States Density

Area of Science:

• Materials Science
• Solid-State Physics
• Radiation Detection

Background:

• Surface trapping and carrier recombination are critical limitations in high-performance light-harvesting and radiation detection devices.
• Organic-inorganic hybrid perovskites, such as MAPbBr3, offer promising properties for radiation detection but require surface optimization.
• Controlling interfacial properties is essential for minimizing charge carrier losses and enhancing device efficiency.

Purpose of the Study:

• To investigate the use of aluminum zinc oxide (AZO) as an anode material for constructing a p-n junction MAPbBr3 nuclear radiation detector.
• To evaluate the impact of AZO/MAPbBr3 interface engineering on carrier recombination and device performance.
• To assess the detector's sensitivity and operational stability under various conditions.

Main Methods:

• Fabrication of a p-n junction detector using AZO/MAPbBr3/Au structure.
• Annealing the AZO/MAPbBr3 interface at 100 °C under an Ar atmosphere to reduce interface state density.
• Characterization of detector performance, including leakage current, photocurrent to dark current ratio, and X-ray sensitivity.

Main Results:

• The AZO/MAPbBr3/Au detector demonstrated a low leakage current (∼9 nA) and high electrical field tolerance (500 V·cm-1).
• Annealing reduced the interface state density from 2.17 × 10^10 to 8.7 × 10^8 cm^-2.
• Achieved a photocurrent to dark current ratio of 190 under green light and a high X-ray sensitivity of ∼529 μC·Gyair^-1 cm^-2.

Conclusions:

• Surface engineering using AZO as an anode material effectively suppresses carrier recombination in MAPbBr3 detectors.
• The optimized detector exhibits superior performance characteristics compared to standard devices.
• These findings highlight the potential of engineered MAPbBr3 detectors for low-dose medical and security applications.