Dr. Michele Back, Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, via Torino 155, 30172 Venezia – Mestre, Italy

Biography: Dr. Michele Back obtained both his B.Sc and M.Sc in Materials Science at Ca’ Foscari University of Venice, Italy in 2010 and 2012, respectively. He completed his Ph.D degree cum laude in Chemical Sciences at Ca’ Foscari University, Italy (January 2017) in the field of optical materials. From October 2015 to April 2016 he spent six months internship for a research collaboration at the Photonic Materials Laboratory of Kyoto University, Japan.
His research interests include the design of bulk and nanoscale materials (nanocrystals and thin films) with advanced optical properties for applications in the fields of bioimaging, telecommunication and phosphors. Currently his research is focused on the synthesis and characterization of bismuth-based luminescent materials. He is author of 15 peer-reviewed publications and 2 international patents.

Speech Title: Near-Infrared Emitting Bi₂Ga₄O₉:Cr³⁺ System: A New Candidate for Ratiometric Optical Thermal Sensing
Abstract: Temperature is a fundamental thermodynamic parameter playing a key role in many biological and technological processes. Among the different strategies proposed in the last decades, ratiometric optical thermometry based on fluorescence intensity ratio (FIR) method has been recognized as the most promising technique. However, the design of single-doped ratiometric luminescent thermal sensors is still a challenge. In this view, many efforts were devoted to the design of ratiometric optical thermometers, but, up to now, only lanthanide-based single-doped materials (e.g. Gd₂O₃:Nd³⁺ and LaF₃:Nd³⁺) seems to meet the requirements of an ideal biological luminescent thermometer.
In this work a spectroscopic investigation of the Bi₂Ga₄O₉:Cr³⁺ system was performed. The PL spectra show the simultaneous sharp and broadband emissions from ²Eg → ⁴A_2g and ⁴T_2g → ⁴A_2g transitions in a wide range of temperature, within the first biological optical window. The reliability of the measurements was assessed comparing the experimental results with theoretical models reported in literature. Moreover, the temperature dependence of emission intensity and lifetimes were discussed and the relative sensitivity was calculated. The results support the suitability of Bi₂Ga₄O₉:Cr³⁺ system as a new candidate for ratiometric luminescent thermal sensing with potential application in biological field.
Keywords: Chromium; Ratiometric Optical Thermometer; Bismuth Gallate; Luminescence