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.

Advantages of MHPs

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 allow MHPs to 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.

Research Objectives

X-PECT aims for a fundamental understanding of the intrinsic strengths and limitations of MHPs as photoactive material for X-ray detection. 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. This will help identify and suppress the factors 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.