Applications of upconversion emissions as a probe to investigate structural-order

Abstract

Spectroscopic investigations of optical emission from materials can be used to estimate the structural properties and provides valuable information about the physical properties at the molecular level. Upconversion is referring as an anti-Stoke emission process that converts long-wavelength excitation into the short-wavelength emission. In this chapter, we have presented a comprehensive analysis of photo luminescence and upconversion emissions which were used to probe the orderness of crystalline structure in the core@shell system. Upconversion emitting lanthanide element doped materials were used to estimate the structural-order which were synthesized by polymeric precursor method (PPM) and hydrothermal method coupled with microwave (HTMW) methods. Results indicate an efficient energy migration upconversion when system is structurally ordered. On the other hand, structural disorder produces defects which desiccate energy transfer process and so the upconversion emission.