Details

Autor(en) / Beteiligte

• Ma, Zhuang-Zhuang
• Shi, Zhi-Feng
• Wang, Lin-Tao
• Zhang, Fei
• Wu, Di
• Yang, Dong-Wen
• Chen, Xu
• Zhang, Yu
• Shan, Chong-Xin
• Li, Xin-Jian

Titel

Water-induced fluorescence enhancement of lead-free cesium bismuth halide quantum dots by 130% for stable white light-emitting devices

Ist Teil von

• Nanoscale, 2020-02, Vol.12 (6), p.3637-3645

Ort / Verlag

England: Royal Society of Chemistry

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Recently, the discovery and development of lead-free perovskite quantum dots (QDs) that are eco-friendly and stable has become an active research area in low-cost lighting and display fields. However, the low photoluminescence quantum yield (PLQY) caused by the residual surface states of such QDs severely hinders their practical applications and commercialization. In this work, a strategy of employing water-induced nanocomposites was proposed to improve the PLQY of cesium bismuth halide (Cs 3 Bi 2 X 9 ) QDs, and a substantial enhancement by ∼130% (from 20.2% to 46.4%) was achieved by an optimized water treatment of Cs 3 Bi 2 Br 9 QDs. A detailed analysis indicated that Cs 3 Bi 2 Br 9 /BiOBr nanocomposites, in which the Cs 3 Bi 2 Br 9 QD core was encapsulated into a BiOBr matrix, can effectively suppress the surface defects of QDs, resulting in a longer PL lifetime and a larger exciton binding energy compared with the pristine sample. Finally, the Cs 3 Bi 2 Br 9 /BiOBr nanocomposites were used as the color-converting phosphors for down-conversion white light-emitting devices, which show a good operation stability in ambient air, significantly better than the reference device constructed with conventional lead-halide perovskites. We believe that the method used here provides an effective strategy to improve the fluorescence efficiency of lead-free perovskite QDs, which will create opportunities for their applications in lighting and displays. We proposed a strategy of employing water-induced Cs 3 Bi 2 Br 9 /BiOBr nanocomposites to achieve a substantial enhancement in photoluminescence quantum yield by ∼130%.