Influence of the non-thermally coupled three-photon band on the performance of Y2O3: Yb3+/Er3+ single-particle nanothermometers

Allison R. Pessoa, Jefferson A.O. Galindo, Luiz F. dos Santos, Rogéria R. Gonçalves, Stefan A. Maier, Leonardo S. de Menezes, Anderson M. Amaral

Research output: Chapter in Book/Report/Conference proceedingConference PaperOtherpeer-review


Nanoscale temperature sensing is increasingly being explored to study physical-chemical processes at the nanoscale. Since direct contact thermometers, like thermistors, are usually not suitable for high spatial resolution applications, luminescence thermometry raises as an alternative. In this case, a nanoparticle can be used as a probe and the temperature measurement is done by analyzing the luminescence emission. One of the most exploited candidates as luminescence nanothermometer probes are dielectric nanoparticles doped with lanthanide ions (Ln3+). They offer a high photostability and the possibility of using non-cytotoxic host matrices, targeting biological applications. In a typical approach, one can measure the temperature from Ln3+-based systems by recording their emission luminescence spectrum and computing the Luminescence Intensity Ratio between two so-called thermally coupled levels [1], which should follow the Boltzmann distribution. Another great advantage of using Ln3+-doped systems is to exploit the upconversion (UC) process, being possible to excite the thermally coupled levels with light of lower energy. In this sense, codoped Yb3+/Er3+ systems are among the most efficient ones. In such cases, the electrons in the ground state of the Yb3+ ions can be excited with a laser near 980 nm. Depending on the Yb3+ and Er3+ ions' proximity, the energy can be efficiently transferred from Yb3+ to Er3+ ions. Consecutive energy transfer (ET) steps can thus lead to the UC phenomena, populating higher-lying electronic states. In Er3+ ions, the thermally coupled levels, 2H11/2 and 4S3/2 need a two-step ET of 977 nm excitation. They decay radiatively to the ground state (4I15/2) resulting in luminescent bands in the green spectral region, with central wavelengths of ∼525 nm and ∼550 nm, respectively. Depending on the excitation power density, higher-order multiphoton absorption can also happen, therefore populating states above the thermally coupled ones.

Original languageEnglish
Title of host publication2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023
Place of PublicationUnited States
PublisherIEEE, Institute of Electrical and Electronics Engineers
Number of pages1
ISBN (Electronic)9798350345995
ISBN (Print)9798350346008
Publication statusPublished - 2023
EventConference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference (CLEO/Europe-EQEC 2023) - Munich, Germany
Duration: 26 Jun 202330 Jun 2023


ConferenceConference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference (CLEO/Europe-EQEC 2023)
Abbreviated titleCLEO/Europe-EQEC 2023
Internet address

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