Self-sensitization induced upconversion of Er3+ in core–shell nanoparticles. Issue 37 (18th September 2018)

• Record Type: Journal Article
• Authors: Yan, Long; Zhou, Bo; Song, Nan; Liu, Xuelong; Huang, Jinshu; Wang, Ting; Tao, Lili; Zhang, Qinyuan
• Is Part Of: Nanoscale. Volume 10:Issue 37(2018)
• Page Start: 17949
• Page End: 17957
• Publication Date: 2018-09-18
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c8nr04816a
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : An in-depth mechanistic investigation on self-sensitized upconversion (SSU) is presented, which would contribute much to both fundamental research and practical applications of lanthanide-based luminescent materials. Abstract : A mechanistic study of upconversion from lanthanides is of great importance for the fundamental research of upconversion materials and their diverse frontier applications. However, the most efficient upconversion of lanthanides is still obtained in a commonly used sensitizer–activator coupled system. Here we report a mechanistic investigation on the upconversion of Er 3+ through self-sensitization which is applicable for 808, 980 and 1530 nm excitations. It is found that the cooperative energy transfer upconversion followed by cross-relaxation occurring among Er 3+ ions plays a critical role in producing and enhancing the red upconversion for the samples with high dopant concentrations ( e.g., >20 mol%). The red upconversion color can be further purified and enhanced by mediating the upconversion dynamics through introducing the lanthanides of Ho 3+, Tm 3+ and Yb 3+, which can effectively contribute to the population in the red emitting state. Moreover, the energy migration in the Er-sublattice was also found to be a possible origin for quenching upconversion, which was proved and effectively suppressed by designing a tri-layered nanostructure where the distribution of Er 3+ is spatially controllable. Our results gain access into the insight of upconversion dynamics in self-sensitization induced upconversion which would help the search for other new kinds of upconversion materials.