Presentation from the SIF Final Event: Choose EUTOPIA for Science: MSCA COFUND Science and Innovation Fellowship impact and careers
Characterization of organic semiconductors using advanced surface-sensitive techniques
My research focuses on the characterization of organic semiconductors using advanced surface-sensitive techniques, with the aim of gaining a profound understanding of the microstructure and electronic properties of these complex materials at the single-molecule level. This knowledge will provide new perspectives for the rational design and optimization of organic electronic devices with improved performance and functionality.
SINGH
Ferroelastic phase transitions
The materials that power our modern technologies possess hidden internal structures that dictate exactly how they behave. When certain advanced materials are created, they naturally form microscopic, alternating patterns known as twins. These nanoscale twins act like a structural patchwork, directly controlling crucial properties like magnetism and electricity.
For years, scientists have struggled to see this patchwork easily with high resolution. Traditional methods are highly restrictive and complicated to operate. They often require us to physically destroy the sample to look inside, rely on massive, expensive facilities, or only work on a very narrow range of materials.
In our research, we demonstrate a simple solution using a technique called Electron Channeling Contrast Imaging (ECCI). We took a standard piece of laboratory equipment, a scanning electron microscope (SEM) and used it to gently bounce a beam of electrons off the crystal lattice of the material. Because each microscopic twin sits at a slightly different angle, they scatter the electrons back differently. By capturing these bouncing electrons, we can create a highly detailed map of the hidden structures without damaging the sample.
This method proved incredibly versatile. We successfully mapped domains as small as 6 nanometres across a wide variety of materials, including metals and layers buried deep within complex devices. This technique provides researchers with a fast, non-invasive, and highly accessible window into the nanoscale world, ultimately helping us to design and build the next generation of smart materials and electronic devices.
Related Paper: A Singh et. al., Electron channeling contrast imaging of ferroelastic domains. Advanced Materials, 38(13), 10.1002/adma.202515762 2026 (IF: 27)
Curriculum Vitae
Xiaocui Wu, PhD
- Education
Sept. 2011 – Jun. 2015 – Bachelor of Nuclear Engineering, IFCEN, Sun Yat-sen University, Zhuhai, China.
Sept. 2015 – Jun. 2017 – Master of Nuclear Engineering & Technology, Sino-French Institute of Nuclear Energy (IFCEN), Sun Yat-sen University, Zhuhai, China.
Oct. 2017 –Sept. 2020 – PhD in Physical Chemistry, CNRS-Chimie Paristech, PSL University, Paris, France.
- Experience
Nov. 2020 – Research associate in Physical Chemistry, Centre National de la Recherche Scientifique (CNRS), Pais, France.
Dec. 2020 – Sept. 2021 – Research associate in Surface Physics, Department of Experimental Physics, Technische Universität Ilmenau, Ilmenau, Germany.
Research Project:
Imaging Structural and Electronic Properties of Conjugated Polymers
The majority of conjugated polymers employed in healthcare, electronics, and energy applications are based on complex chemical compositions and structures obtained through multi- and co-polymerization techniques. The success of these materials relies on the versatility of polymer chemistry as it enables the targeting of specific architectures, electronic properties, and therefore, functions. However, the increased complexity of the materials also increases the challenges in determining their detailed chemical structure, their function directing microstructure, and their detailed electronic characteristics. Traditional analytical techniques used in polymer science (crystallography, magnetic resonance, chromatography) are often struggling to precisely characterize modern conjugated polymers and this represents a significant limitation to progress in the field.
Here we propose to solve this fundamental problem by using the ultimate spatial resolution of scanning probe microscopy and its ability to provide images and local electronic properties of molecules with sub-monomer precision. Based on a recent breakthrough of the host lab in submolecular resolution imaging of conjugated polymers, this project intends to achieve unprecedented insight into the composition, structure, and electronic properties of these functional macromolecules. Following this approach, conjugated polymers will be sequenced by simple visual inspection of their images, revealing details inaccessible to standard characterizations methods such as the structure of polymerization defects and the spatial distribution of their molecular orbitals.