Controllable crystallization based on the aromatic ammonium additive for efficiently near-infrared perovskite light-emitting diodes

Abstract

Organic-inorganic hybrid perovskite have recently drawn appreciable attention for applications in light-emitting diodes (LEDs). However, the weak exciton binding energy of the methylammonium lead iodide perovskite introduces large exciton dissociation and low radiative recombination on its application as emission layer in near-infrared LEDs. Herein, we demonstrate the simple method by incorporating of phenethylammonium iodide (PEAI) into the perovskite can concurrently improve the radiative recombination rate for improving perovskite LED performances. Additionally, by introducing PEAI dramatically constrains the growth of perovskite crystals during film forming, producing crystallites with small dimensions, reducing roughness, and pin-hole free. After optimizing the emission layer in the perovskite LED, a high optical output power of 458.03 μW and external quantum efficiency of 5.25% are achieved, which represents a ~50-fold enhancement in the quantum efficiency compared to device without PEAI. Our work suggests a broad application prospect of perovskite materials for high optical output power LEDs and eventually a potential for solution-processed electrically pumped NIR laser diodes. • The mixing of PEAI in the perovskite precursor can effectively reduce the size of the perovskite crystals • Photoluminance and electroluminance intensity becomes stronger with increasing additive concentration • A pin-holes free thin films are achieved when adding the PEAI • Tremendous reduction in turn-on voltage and outstanding improvement of output power