Synthesis and enhanced photo/thermal stability of high-luminescent red-emitting CdTe@CaCO3 composite for LED applications. Issue 5 (1st April 2019)

• Record Type: Journal Article
• Authors: Zhang, Xinguo; Sun, Zishan; Zhou, Chunyan; Zhu, Zhenpeng; Guo, Ziying; Shen, Jinhai; Lin, Yuxuan; Xiao, Shuang; Chen, Liang; Zheng, Xihua; Wu, Zhan-chao
• Is Part Of: Ceramics international. Volume 45:Issue 5(2019)
• Page Start: 6484
• Page End: 6490
• Publication Date: 2019-04-01
• Subjects: Composite material -- Quantum dots -- Luminescence -- LED; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2018.12.137
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: High-luminescent CdTe@CaCO3 composite with strong and stable solid-state red emission (PLQY = ~ 50%) is synthesized via a facile co-precipitation method. The composite particles show rice-like shape with narrow size distribution, non-agglomeration, and smooth surface. A continuous tune of emission wavelength from 690 to 660 nm is achieved by increasing CaCO3 coating proportion. Compared with solid-state CdTe QDs powder, CdTe@CaCO3 composites exhibits a greatly enhancement in emission intensity (280% of initial intensity), remarkably enhancement of photostability (90% after 12 h UV irradiation) and thermal stability (70% at 180 °C). Those improvements are attributed to the effective protection and surface passivation of coated CaCO3 layer on CdTe cores. Using yellow-emitting YAG phosphor and red-emitting CdTe@CaCO3 composite as color-converted layer, the fabricated white LED prototype exhibits high color rendering index (94.3) and low color temperature (3964 K) with proper CIE coordinates (0.3773, 0.3604).