Engineering

Materials science

Layer (electronics)

Perovskite (structure)

Photoluminescence

Inorganic chemistry

Chemical engineering

Quantum yield

Grain boundary

Physics

Quantum efficiency

Nanotechnology

Organic chemistry

Optics

Microstructure

Fluorescence

Composite material

Chemistry

Nucleation

Light-emitting diode

Optoelectronics

Halide

Passivation

Nature Communications

Quantum efficiencies of organic-inorganic hybrid lead halide perovskite light-emitting devices (LEDs) have increased significantly, but poor device operational stability still impedes their further development and application. All-inorganic perovskites show better stability than the hybrid counterparts, but the performance of their respective films used in LEDs is limited by the large perovskite grain sizes, which lowers the radiative recombination probability and results in grain boundary related trap states. We realize smooth and pinhole-free, small-grained inorganic perovskite films with improved photoluminescence quantum yield by introducing trifluoroacetate anions to effectively passivate surface defects and control the crystal growth. As a result, efficient green LEDs based on inorganic perovskite films achieve a high current efficiency of 32.0 cd A −1 corresponding to an external quantum efficiency of 10.5%. More importantly, our all-inorganic perovskite LEDs demonstrate a record operational lifetime, with a half-lifetime of over 250 h at an initial luminance of 100 cd m −2 .

Trifluoroacetate induced small-grained CsPbBr3 perovskite films result in efficient and stable light-emitting devices