New Method Creates Ultra-Uniform Quantum Dot Films for Next-Generation Electronics

A research team led by Prof. Maria Antonietta Loi has developed a breakthrough technique to produce exceptionally uniform and crack-free thin films made from quantum dots—tiny semiconductor crystals with unique optical and electronic properties. The study, published as “Langmuir-Schaefer Deposition of 2D PbS Quantum Dot Superlattices with Millimetre Square Coverage,” opens new possibilities for advanced technologies such as infrared cameras, sensors, and high-performance electronics.

Quantum dots are often described as “artificial atoms” because of their tunable properties, which make them highly attractive for future devices. However, assembling them into large, defect-free films has long been a challenge. In particular, two-dimensional (2D) arrangements of quantum dots often develop cracks and irregularities, which limit their performance.

The research team overcame this hurdle by applying gentle pressure during the assembly process. This simple but effective step prevents the films from cracking, creating smooth, ordered layers that can extend over millimeter-scale areas. Advanced computer simulations by the group of Dr. Andrea Giuntoli revealed how pressure helps the quantum dots pack together more efficiently, while electrical tests showed excellent performance: the films exhibited electron mobilities above 25 cm²/Vs, a significant improvement over conventional approaches.

“This is the first time that large, crack-free 2D quantum dot superlattices with such high charge mobility have been achieved,” Prof. Loi noted. “Our method could pave the way for scalable production of quantum dot films in optoelectronic devices.”

By solving a long-standing bottleneck in film quality, this work moves quantum dot technologies closer to practical applications in areas ranging from medical imaging to next-generation consumer electronics.

Reference: Langmuir-Schaefer Deposition of 2D PbS Quantum Dot Superlattices with Millimetre Square Coverage, Jacopo Pinna, Alexandru Mednicov, Razieh Mehrabi Koushki, Majid Ahmadi, José Ruiz-Franco, Andrea Giuntoli, Bart J. Kooi, Giuseppe Portale & Maria Antonietta Loi, Nature Communications volume 16, Article number: 9008 (2025)