The article, entitled "Echoes from quantum confinement", by Alejandro Goñi, reviews the article "Intrinsic quantum confinement in formamidinium lead triiodide perovskite"  by Adam D. Wright, George Volonakis, Juliane Borchert, Christopher L. Davies, Feliciano Giustino, Michael B. Johnston and Laura M. Herz from the University of Oxford. 

"The recently discovered above-gap oscillations in the optical absorption of formamidinium lead triiodide by Wright et al. are a manifestation of the fascinating intrinsic quantum effects being hosted by this class of hybrid organic/inorganic perovskite semiconductors. Understanding the mechanisms leading to such phenomenon may open a new route for tailoring their electronic band structure at the nanoscale to enhance optoelectronic performance by exploiting the confinement-induced discretization of the energy spectrum." says Alejandro Goñi.

Goñi is ICREA Research Professor at the Nanostructured Materials for Optoelectronics and Energy Harvesting (NANOPTO) research group at the ICMAB . He is an experimental physicist with broad interests and expertise in solid-state physics, optical spectroscopy (Raman scattering, photoluminescence, etc.), nano-science and technology, thermoelectricity, the physics of low-dimensional materials (quantum wells, wires and dots), highly correlated electron systems, and high-pressure techniques. Many of his most recent publications are related to hybrid perovskites and the study of their properties. 

Cover Figure: Above-gap oscillations observed in the absorption spectra of FAPbI₃ thin films at different temperatures. The inset shows two concurrent mechanisms that may lead to the oscillations: strict quantum confinement in deep wells and the periodicity of a superlattice confining potential. Black lines represent the distribution along the spatial coordinate x of the energy potential E; red lines represent the discrete energy levels or mini-bands formed in the electronic band structure of the material | Nat. Mater. 2020

Referenced articles:

Goñi, A.R. Echoes from quantum confinement. Nat. Mater. (2020). DOI: 10.1038/s41563-020-0796-3

Wright, A.D., Volonakis, G., Borchert, J. et al. Intrinsic quantum confinement in formamidinium lead triiodide perovskite. Nat. Mater. (2020). DOI: 10.1038/s41563-020-0774-9