Researchers found that the performance of Sn perovskite LEDs can be improved by forming epitaxial heterodimensional films using spin coating. These films consist of a two-dimensional and a three-dimensional perovskite layer, which have a highly ordered structure and a clearly defined interface with minimal interdimensional areas.

Environmentally friendly tin (Sn) perovskites have received considerable attention due to their great potential for replacing their toxic lead counterparts in applications of photovoltaics and light-emitting diodes (LEDs). However, the device performance of Sn perovskites lags far behind that of lead perovskites, and the highest reported external quantum efficiencies of near-infrared Sn perovskite LEDs are below 10%. The poor performance stems mainly from the numerous defects within Sn perovskite crystallites and grain boundaries, leading to serious non-radiative recombination. Various epitaxy methods have been introduced to obtain high-quality perovskites, although their sophisticated processes limit the scalable fabrication of functional devices.