Details

Autor(en) / Beteiligte

• Wei, Zhanhua
• Perumal, Ajay
• Su, Rui
• Sushant, Shendre
• Xing, Jun
• Zhang, Qing
• Tan, Swee Tiam
• Demir, Hilmi Volkan
• Xiong, Qihua

Titel

Solution-processed highly bright and durable cesium lead halide perovskite light-emitting diodes

Ist Teil von

• Nanoscale, 2016-11, Vol.8 (42), p.18021-18026

Ort / Verlag

England

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Recently, CsPbBr perovskites have been emerging as very promising green emission materials for light-emitting diodes (LEDs) due to their high color purity, low cost and high photoluminescence quantum yield (PLQY). However, the corresponding LED performance is still low and far behind CH NH PbBr ; it is due to the lack of proper perovskite film preparation methods and interfacial engineering. Herein, we report highly bright and durable CsPbBr -based LEDs fabricated using a one-step solution method. The precursor solution is prepared by simply dissolving CsPbBr powder and a CsBr additive in dimethyl sulfoxide (DMSO). We find that the CsBr additive not only significantly enhances the PLQY but also induces directional crystal growth into micro-plates, forming a smooth perovskite film for LEDs. LEDs employing such high quality films show a high luminance of 7276 cd m and high color purity with a full width at half maximum of 18 nm. Furthermore, the as-fabricated LEDs reveal an outstanding ambient stability with a decent luminance output (>100 cd m , steady increase without any degradation trend) for at least 15 h under a constant driving current density (66.7 mA cm ). And we propose two reasons for this unique luminance increasing behavior: (1) the CsPbBr perovskite is thermally stable and can survive from joule heat; and (2) on the other hand, the joule heating will induce interface or crystalline film annealing, reduce device resistance and then enhance the luminance output.