Ultrafast quantum effects discovered in low-cost materials

Breakthrough in perovskite films could accelerate the development of quantum technologies

Cambridge, UK/Jülich, Garching and Munich, Germany – 13 November 2025. A research team led by Professor Samuel D. Stranks at the University of Cambridge, UK, has observed ultrafast quantum phenomena in a simple, low-cost semiconductor material — a breakthrough that could make future quantum devices faster and more affordable. In a new paper published in Nature Nanotechnology, the researchers report the first observation of picosecond-scale quantum transients — light emission processes lasting just trillionths of a second — in formamidinium lead iodide (FAPbI₃) films. These effects arise naturally within nanodomain superlattices inside the material, without the need for expensive, precisely engineered structures.

Halide perovskites are promising materials for optoelectronic devices such as solar cells, light-emitting diodes, and quantum light sources. However, achieving the ultrafast emission rates required for advanced quantum applications has typically been limited to expensive, epitaxially grown III-V materials. The research team has now discovered that bulk formamidinium lead iodide (FAPbI₃) films, fabricated using scalable solution or vapour methods, can exhibit quantum emissions with ultranarrow linewidths (<2 nm) and decay times on the picosecond scale.

Using a multimodal strategy that combines ultrafast spectroscopy, cryogenic hyperspectral photoluminescence microscopy, and scanning electron diffraction, the researchers pinpointed the structural origin of these quantum effects: layered, nano-twinned superlattices formed by alternating corner-sharing and face-sharing octahedra. This periodic structure creates a natural, intrinsic quantum-confined environment analogous to a Kronig-Penney superlattice.

The primary contribution to this research came from the team at the University of Cambridge, which managed the sample fabrication, ultrafast spectroscopic measurements, structural analysis, and data modelling. Cryogenic small- and wide-angle X-ray scattering (SAXS/WAXS) measurements, crucial for understanding the low-temperature structural behaviour, was provided by Dr. Baohu Wu at the Jülich Centre for Neutron Science (JCNS) at the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching near Munich and Dr. Renjun Guo and Prof. Peter Müller-Buschbaum from the Department of Physics at the Technical University of Munich (TUM).

This discovery demonstrates that ultrafast quantum phenomena, previously only attainable in meticulously engineered materials, can be intrinsically found in inexpensive, easily fabricated perovskite films. It opens new pathways for the design of high-performance quantum emitters for applications in ultrafast computing, communication, and sensing. Furthermore, the multimodal approach established in this study provides a powerful, transferable platform for investigating structure-property relationships in a wide range of advanced materials.

Original publication:
Dengyang Guo, Thomas A. Selby et al. "Picosecond quantum transients in halide perovskite nanodomain superlattices." Nature Nanotechnology (2025).
https://doi.org/10.1038/s41565-025-02036-6

Information on the SAXS/WAXS Laboratory Beamline of JCNS at the MLZ:
SAXS Lab / MLZ