Spacer cation enabled dimension control for efficient and wavelength-tunable blue perovskite light-emitting diodes

This study explores a conjugated spacer molecule, biphenylethylammonium bromide (bPEA), to enable efficient dimension control in quasi-two-dimensional perovskites for blue light-emitting diodes. The incorporation of bPEA improves the optoelectronic properties, thereby delivering a peak external quantum efficiency of 7.0% at 483 nm and tunable emission from 493 to 466 nm.