Toward next-generation X-ray imaging: Pb-free PErovskite Charge Transport engineering

Introduction

X-rays are widely applied in medical diagnostics, security screening, and scientific research. The growing demand for X-ray imaging has increased the frequency with which humans are exposed to ionizing X-rays, directly increasing radiation-related health risks.

Project Goals

To minimize these health risks, X-PECT aims to rationally design materials that enable more sensitive X-ray detectors, thus allowing the use of lower operational radiation doses.

Material Focus

Metal halide perovskite (MHP) semiconductors have emerged as a highly promising material class for sensitive X-ray detection. Besides their easy processing, the popularity of MHPs arises from their outstanding optoelectronic properties, such as:

• Strong high-energy X-ray absorption
• Efficient charge carrier generation and transport

These properties outperform current market standards.

Challenges

However, the intrinsic instability and toxicity of popular lead-based MHPs hinders their large-scale application in sustainable X-ray technology. X-PECT aims for a fundamental understanding of the intrinsic strengths and limitations of MHPs as photoactive material for X-ray detection.

Scientific Hurdles

In this context, X-PECT will address urgent scientific hurdles related to:

1. Toxicity
2. Structural and chemical stability
3. Intrinsic charge carrier transport efficiency
4. Processing efforts

Ultimate Goal

The ultimate goal of X-PECT is to rationally develop highly sensitive, sustainable lead-free MHPs through micromanaging their electronic structure by composition and dimensionality engineering.

Methodology

Tailoring their functionality will be guided by applying a full arsenal of both established characterization techniques and unique (micro)spectroscopy platforms for the full assessment of the structural and photophysical properties to identify and suppress the factor(s) currently limiting the X-ray sensitivity and stability.

Final Outcome

Ultimately, selected candidate materials will be processed into a stable, scalable pixelated X-ray demonstrator device with a 20- to 50-fold improved sensitivity and resolution.