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Two-dimensional tin perovskite nanoplate for pure red light-emitting diodes

Halide perovskites are rising as promising luminescent materials for display applications for their sharp emission peaks and high luminescence quantum yield. However, the heavy metal character of lead is one concern that shadows its application. In this work, monolayer Ruddlesden–Popper 2D structural tin perovskite (PEA)2SnI4 (PEA = C8H9NH3+) is explored for a pure red color light emitting diode (LED). The manipulation of crystal growth kinetics enables the formation of highly ordered nanoplates, bringing high luminescence yield approaching 10% with an emission peak at 630 nm. Meanwhile, the highly oriented and ordered nanoplates structure allows effective carrier injection. The LED shows a low turn on voltage of 2.2 V, an external quantum efficiency of 0.52% and a max luminance of 355 cd m−2. The luminescence quantum yield is comparable to the best performing device based on lead perovskites in the pure red emission region. This work provides a strategy to explore 2D structures for efficient macroscale LEDs.