A study of twisted two-dimensional semiconductors reveals how subtle material disorder can emerge at different spatial scales.

Two distinct forms of hidden disorder may influence how ultrathin semiconductors emit light. One extends across relatively large areas of the material, while the other is concentrated around tiny defects. A new theoretical approach offers a way to identify these patterns by analyzing changes in light emission rather than attempting to separate individual spectral signals.

Developed by Katsunori Wakabayashi at the Research Center for Materials Nanoarchitectonics (MANA), part of the National Institute for Materials Science (NIMS), the framework could provide a more reliable way to investigate imperfections in materials used for advanced optical and quantum devices.