时 间： 2012年7月2日上午10:00点
地 点： 四川大学物理科学与技术学院一楼会议室
报告题目：

New organolanthanides materials for infra-red to visible upconversion. High Pressure techniques as a tool for opto-structural correlations.

报告人：

Ignacio Hernandez

CCMMP, School of Physics, Queen Mary University of London – Department. of Earth Sciences and Condensed Matter, Universidad de Cantabria

Abstract:The use of trivalent lanthanides in combination with organics for optical applications provides a route for higher performances in contrast with their inorganic counterparts. This is due to their enhanced processability, the fine tuning of the concentration of optically active centres and the possibility of indirect excitation through the more allowed optical transitions in the organic part. However, poor efficiencies are obtained when the organic matrix contains hydrogen and the energy gap between the electronic states is low, which is the case for excitations in the infra-red range. The use of perhalogenated ligands and the complete removal of solvent molecules can solve this problem bearing relatively long-lived excited states which are of interest for laser and optical amplification purposes. In a recent work we discovered that cross-relaxation mechanisms, involving energy exchange between pairs of long lived erbium ions, were taking place [1]. This understanding has allowed us to produce the first instance of organolanthanide-based IR-to visible upconverting polymers. These simple, cheap and easily synthesised materials show comparable efficiencies to those obtained in inorganic compounds [2].

We face this research with an underlying desire for design rules based on opto-structural correlations and, conversely, due to our background in high pressure, our research can serve to understand the structural properties of these and related materials. The interplay between chemical composition, structure and optical properties is thus a key target. High pressure techniques can be crucial for understanding these and some examples will be given.

[1] I. Hernandez et al. Journal of Physical Chemistry B 113, 7474-7481 (2009)

[2] I. Hernandez et al. Advanced Materials 22, 5356–5360 (2010)

                            四川大学物理科学与技术学院

                                   2012-06-26