Yuan Fang, Liu Xiaoyun, Zhang Songting, Zhu Peichao, Ali Fawad, Zhao Chenjing, He Shuaiqi, Ma Qianhao, Li Jingrui, Guo Kunping, Li Lu, Wu Zhaoxin
Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Branch of LONGi Green Energy Technology Co., Ltd. in XixianNew Area, No. 215 Jinggan Second Street, Yongle Town, Jinghe Xincheng, Xixian New Area, Xi'an 710018, China.
Nanomaterials (Basel). 2024 Nov 28;14(23):1919. doi: 10.3390/nano14231919.
Achieving deep-blue light with high color saturation remains a critical challenge in the development of white light-emitting diode (LED) technology, necessitating luminescent materials that excel in efficiency, low toxicity, and stability. Here, we report the synthesis of [N(CH)]CuI (TEACuI) single crystals (SCs), which exhibit deep-blue photoluminescence (PL) at 450 nm. These crystals are characterized by a significant Stokes shift of 180 nm, a long lifetime of 1.7 μs, and an impressive photoluminescence quantum yield (PLQY) of 96.7% for SCs and 87.2% for polycrystalline films. The zero-dimensional structure is attributed to the proper spacing of triangular inorganic units [CuI] by organic cations [N(CH)]. This structural arrangement facilitates broadband deep-blue light emission with phosphorescent characteristics, as evidenced by temperature-dependent PL and time-resolved photoluminescence (TRPL) measurements. The band gap properties of TEACuI were further elucidated through density functional theory (DFT) computations. Notably, the material exhibited minimal PL intensity degradation after continuous UV irradiation and one month of exposure to ambient conditions. Moreover, the polycrystalline film of TEACuI maintained substantial deep-blue emission even after one year of storage. Utilizing TEACuI thin film, we fabricated an electroluminescent device emitting deep-blue light with high color saturation, featuring CIE coordinates (0.143, 0.076) and a brightness of 90 cd/m. The exceptional photophysical properties of TEACuI render it a highly promising candidate for optoelectronic applications.
在白光发光二极管（LED）技术的发展中，实现具有高色彩饱和度的深蓝色光仍然是一项关键挑战，这就需要在效率、低毒性和稳定性方面表现出色的发光材料。在此，我们报道了[N(CH)]CuI（TEACuI）单晶（SCs）的合成，其在450 nm处呈现深蓝色光致发光（PL）。这些晶体的特征在于180 nm的显著斯托克斯位移、1.7 μs的长寿命以及令人印象深刻的光致发光量子产率（PLQY），单晶为96.7%，多晶薄膜为87.2%。零维结构归因于有机阳离子[N(CH)]对三角形无机单元[CuI]的适当间距。这种结构排列有助于具有磷光特性的宽带深蓝色光发射，这通过温度相关的PL和时间分辨光致发光（TRPL）测量得到证实。通过密度泛函理论（DFT）计算进一步阐明了TEACuI的带隙特性。值得注意的是，该材料在连续紫外照射和暴露于环境条件一个月后，PL强度降解最小。此外，TEACuI的多晶薄膜即使在储存一年后仍保持大量的深蓝色发射。利用TEACuI薄膜，我们制造了一种发射具有高色彩饱和度的深蓝色光的电致发光器件，其CIE坐标为（0.143, 0.076），亮度为90 cd/m。TEACuI优异的光物理性质使其成为光电子应用中极具潜力的候选材料。
