Physics

Nanotechnology

Blueshift

Quantum efficiency

Crystallography

Analytical Chemistry (journal)

Optics

Astronomy

Perovskite (structure)

Band gap

Quantum yield

Light-emitting diode

Chemistry

Materials science

Layer (electronics)

Blue light

Spectral line

Diode

Photoluminescence

Electroluminescence

Chromatography

Optoelectronics

Photochemistry

Fluorescence

Nature Communications

Perovskite light-emitting diodes (PeLEDs) have showed significant progress in recent years; the external quantum efficiency (EQE) of electroluminescence in green and red regions has exceeded 20%, but the efficiency in blue lags far behind. Here, a large cation CH 3 CH 2 NH 2 + is added in PEA 2 (CsPbBr 3 ) 2 PbBr 4 perovskite to decrease the Pb–Br orbit coupling and increase the bandgap for blue emission. X-ray diffraction and nuclear magnetic resonance results confirmed that the EA has successfully replaced Cs + cations to form PEA 2 (Cs 1- x EA x PbBr 3 ) 2 PbBr 4 . This method modulates the photoluminescence from the green region (508 nm) into blue (466 nm), and over 70% photoluminescence quantum yield in blue is obtained. In addition, the emission spectra is stable under light and thermal stress. With configuration of PeLEDs with 60% EABr, as high as 12.1% EQE of sky-blue electroluminescence located at 488 nm has been demonstrated, which will pave the way for the full color display for the PeLEDs.

Large cation ethylammonium incorporated perovskite for efficient and spectra stable blue light-emitting diodes