Maria Antonietta Loi (born 4 May 1973) is an Italian physicist who is a Professor of Optoelectronics at the University of Groningen and member of the Zernike Institute for Advanced Materials.

After earning her PhD she moved to the Johannes Kepler University Linz, where she worked as a postdoctoral researcher on organic solar cells.

[3] After one year in Austria she returned to Italy, where she joined the Italian National Research Council Institute for Nanostructured Materials.

[5] Her early work considered the investigation of organic semiconductors and carbon nanotubes photophysical and optoelectronic properties.

[9][10] She has shown that Sn-based perovskites have intriguing physical properties such as showing photoluminescence from hot-carriers with long lifetimes.