TY - JOUR
T1 - Highly Efficient Pure-Blue Perovskite Light-Emitting Diode Leveraging CsPbBrxCl3−x/Cs4PbBrxCl6−x Nanocomposite Emissive Layer with Shallow Valence Band
AU - Choi, In Young
AU - Baek, Sung Doo
AU - Takaloo, Ashkan Vakilipour
AU - Lee, Seung Yong
AU - Hajibabaei, Amir
AU - Kim, Kwang S.
AU - Myoung, Jae Min
N1 - Publisher Copyright:
© 2022 Wiley-VCH GmbH
PY - 2022/3/18
Y1 - 2022/3/18
N2 - Metal-halide perovskite light-emitting diodes (PeLEDs) have shown great advancement in green, red, and near-infrared regions with external quantum efficiencies (EQEs) exceeding 20%. However, blue PeLEDs, an essential part of displays and lightings, show limited progress compared to the other color counterparts. Herein, a highly efficient pure-blue PeLED is demonstrated by leveraging a novel CsPbBrxCl3-x/Cs4PbBrxCl6-x nanocomposite perovskite film as an emissive layer. The Cs4PbBrxCl6-x phase, the derived phase of CsPbBr3 perovskite with a mixed halide system, effectively passivates defects in CsPbBrxCl3-x, leading to high luminescence efficiency due to the significant reduction of nonradiative recombination. Furthermore, experimental and computational results confirmed that the compositionally optimized nanocomposite layer possesses a shallower valence band maximum (≈5.5 eV) than the pristine perovskite layer (≈5.9 eV), which is very advantageous in hole injection for device operation. The combined effects of the CsPbBrxCl3-x/Cs4PbBrxCl6-x nanocomposite render the fabricated blue PeLED to exhibit a pure-blue emission at 470 nm with a maximum EQE of 5.3%.
AB - Metal-halide perovskite light-emitting diodes (PeLEDs) have shown great advancement in green, red, and near-infrared regions with external quantum efficiencies (EQEs) exceeding 20%. However, blue PeLEDs, an essential part of displays and lightings, show limited progress compared to the other color counterparts. Herein, a highly efficient pure-blue PeLED is demonstrated by leveraging a novel CsPbBrxCl3-x/Cs4PbBrxCl6-x nanocomposite perovskite film as an emissive layer. The Cs4PbBrxCl6-x phase, the derived phase of CsPbBr3 perovskite with a mixed halide system, effectively passivates defects in CsPbBrxCl3-x, leading to high luminescence efficiency due to the significant reduction of nonradiative recombination. Furthermore, experimental and computational results confirmed that the compositionally optimized nanocomposite layer possesses a shallower valence band maximum (≈5.5 eV) than the pristine perovskite layer (≈5.9 eV), which is very advantageous in hole injection for device operation. The combined effects of the CsPbBrxCl3-x/Cs4PbBrxCl6-x nanocomposite render the fabricated blue PeLED to exhibit a pure-blue emission at 470 nm with a maximum EQE of 5.3%.
KW - blue light-emitting diodes
KW - nanocomposites
KW - perovskites
KW - shallow valence band maximum
UR - http://www.scopus.com/inward/record.url?scp=85123892370&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85123892370&partnerID=8YFLogxK
U2 - 10.1002/adom.202102502
DO - 10.1002/adom.202102502
M3 - Article
AN - SCOPUS:85123892370
SN - 2195-1071
VL - 10
JO - Advanced Optical Materials
JF - Advanced Optical Materials
IS - 6
M1 - 2102502
ER -