TY - JOUR

T1 - Cation engineering in low-dimensional organic-inorganic copper halides for high color rendering index WLEDs

AU - Yin, Hong

AU - Li, Wenzhi

AU - Wang, Zhongyi

AU - Wang, Pengyuan

AU - Xu, Xin

AU - Han, Peigeng

AU - Mao, Xin

AU - Liu, Feng

AU - Han, Keli

AU - Chen, Junsheng

AU - Zhang, Ruiling

N1 - Funding Information: This work was supported by the project funded by the National Natural Science Foundation of China (Grant No. 22103050 ), the Natural Science Foundation of Shandong Province ( ZR2021QB010 ). J. C. acknowledges support from the Novo Nordisk Foundation (NNF22OC0073582). We are grateful to Xiaoju Li and Haiyan Sui from Shangdong University Core Facilities for Life and Environmental Sciences for their help with the XRD. We are also grateful to Jin Xiong from Carnegie Mellon University for his help with the analysis of single crystal structure. R. Z. acknowledges the financial support from the Program of Young Scholars Future Program of Shandong University. Publisher Copyright: © 2023 Elsevier B.V.

PY - 2023/8/15

Y1 - 2023/8/15

N2 - Searching for single-component white-light emitting materials with excellent color rendering index (CRI) is significant to the development of white-light emitting diodes (WLEDs). Herein, we introduce three different cations with increasing steric hindrance to develop novel luminescent low-dimensional organic copper halides: one-dimensional (1D) ETMACu2I3 (ETMA: ethyltrimethylammonium), 1D TEACu2I3 (TEA: tetraethylammonium), and zero-dimensional (0D) TBMACuI2 (TBMA: tributylmethylammonium). The dimensionality of the prepared copper halides decreases with the increase of the steric hindrance of the organic cations. Meanwhile, the photoluminescence spectra become broader. The two 1D compounds exhibit weak single broad emission originating from self-trapped excitons (STEs) and defects. Interestingly, 0D TBMACuI2 emits bright warm white light with dual emission bands. The mechanism of the unique dual emission is unveiled by systematic spectroscopic study including temperature-dependent and femtosecond transient absorption spectroscopies. Two spin-triplet STE states contribute to the intriguing dual emission. A WLED based on TBMACuI2 can exhibit an ultra-high CRI of 95.7, which is promising for single-component white-light emitting applications.

AB - Searching for single-component white-light emitting materials with excellent color rendering index (CRI) is significant to the development of white-light emitting diodes (WLEDs). Herein, we introduce three different cations with increasing steric hindrance to develop novel luminescent low-dimensional organic copper halides: one-dimensional (1D) ETMACu2I3 (ETMA: ethyltrimethylammonium), 1D TEACu2I3 (TEA: tetraethylammonium), and zero-dimensional (0D) TBMACuI2 (TBMA: tributylmethylammonium). The dimensionality of the prepared copper halides decreases with the increase of the steric hindrance of the organic cations. Meanwhile, the photoluminescence spectra become broader. The two 1D compounds exhibit weak single broad emission originating from self-trapped excitons (STEs) and defects. Interestingly, 0D TBMACuI2 emits bright warm white light with dual emission bands. The mechanism of the unique dual emission is unveiled by systematic spectroscopic study including temperature-dependent and femtosecond transient absorption spectroscopies. Two spin-triplet STE states contribute to the intriguing dual emission. A WLED based on TBMACuI2 can exhibit an ultra-high CRI of 95.7, which is promising for single-component white-light emitting applications.

KW - Copper halides

KW - Lead-free

KW - Photoluminescence

KW - Self-trapped excitons

KW - Ultrafast dynamics

U2 - 10.1016/j.cej.2023.144353

DO - 10.1016/j.cej.2023.144353

M3 - Journal article

AN - SCOPUS:85164515483

VL - 470

JO - Biochemical Engineering Journal

JF - Biochemical Engineering Journal

SN - 1369-703X

M1 - 144353

ER -