A new international study, led by the University of Padua, explores how advanced microscopy techniques are revolutionizing our understanding of semiconductors. Researchers investigated methods such as atom probe tomography, scanning tunneling microscopy, and transmission electron microscopy, which make it possible to observe how atoms are arranged within materials. Thanks to these techniques, it has become clear that both atomic order and disorder significantly affect the properties of semiconductors, including electrical conductivity and light emission efficiency. Surprisingly, a certain degree of disorder can even enhance material performance. Such understanding is crucial for the development of next-generation electronic and optoelectronic devices, enabling continuous improvements in their efficiency.
A recent review by researchers from Italy, France, and the Netherlands provides a comprehensive overview of cutting-edge microscopy techniques - such as atom probe tomography (APT), scanning tunneling
microscopy (STM), and transmission electron microscopy (TEM) - and their role in advancing the study of group III-V semiconductors, key materials for electronics and optoelectronics. The study, led by Enrico Di Russo, researcher of the Semiconductor Group at the Department of Physics and Astronomy of the University of Padua - in collaboration with scientists from the Université de Rouen, CNRS, and Eindhoven
University of Technology - also explores the potential of these techniques for new classes of materials, such as two-dimensional materials and perovskites, while also addressing group IV semiconductors, which remain central to microelectronics.
In the world of semiconductors, the arrangement of atoms in the crystal lattice - whether ordered or disordered - can lead to unexpected outcomes. These phenomena influence key characteristics of semiconductors, such as electrical behavior driven by the presence of dopants, and the ability of materials to emit or absorb light efficiently. Understanding how atoms arrange, cluster, or interact is therefore crucial for the design of high-performance devices such as LEDs, lasers, and solar cells.
The article titled “Order and disorder at the atomic scale: Microscopy applied to semiconductors” traces the historical development of atomic-scale microscopy techniques and explains their working principles. Each technique is illustrated in terms of its strengths: for example, atom probe tomography (APT) enables the construction of 3D maps that reveal both the position and chemical identity of individual atoms; scanning tunneling microscopy (STM) allows the observation of how impurities are distributed on material surfaces; and transmission electron microscopy (TEM) provides ultra-high-resolution images of crystals, making it possible to directly study the atomic-scale structure of semiconductors.
One of the most surprising insights from this research is that disorder, contrary to common belief, is not always detrimental: in some cases, it can actually enhance material performance, for example by inducing
magnetic properties or boosting light emission efficiency. As a consequence, atomic-scale microscopy techniques are no longer merely tools for observing structures, but they are becoming essential
instruments for tailoring and optimizing materials themselves: they allow researchers to engineer disorder by controlling and exploiting it for technological innovation.
The full article is available online in Reviews of Modern Physics:
