The observed quantum effects emerge in films created using scalable approaches, rather than limited laboratory processes. This makes the material a promising candidate for affordable ultrafast quantum technologies. Professor Sam Stranks, who directed the research, stated, "Perovskites continue to surprise us. This discovery shows how their intriguing nanoscale structure gives rise to intrinsic quantum properties that could be harnessed for future photonic technologies."
The team, led by joint first authors Dr Dengyang Guo and PhD student Tom Selby from the Optoelectronic Materials and Device Spectroscopy Group, utilized ultrafast spectroscopy alongside optical and electron microscopy. They traced the rapid emission process to quantum tunnelling in ordered nanodomain superlattices - repetitive structural domains within the films that facilitate rapid radiative recombination.
Dr Guo commented, "Seeing these ultrafast effects in scalable films is exciting. It shows perovskites have even more to offer than we realised, beyond solar cell optimisation."
Selby added, "Being able to trace the emission back to the structure has been an eye-opener - it is really exciting to consider the potential of what this research could lead to."
The study's authors urge both optimism and caution. While the ultrafast transients are promising for uses in rapid emission and precise measurements, the experiments were performed only at low temperature. The paper does not present measurements at room temperature or standard quantum-optics results such as single-photon purity or indistinguishability. Nonetheless, these results illustrate the versatile potential of halide perovskites.