Above and beyond the laser-induced anti-Stokes broadband white light emission in rare-earth-manganese perovskites

Year: 2025

Authors: Ramos T.J.S., Musialek A., Tomala R., Strek W.

Autors Affiliation: Polish Acad Sci, Inst Low Temp & Struct Res, Okolna 2, PL-50422 Wroclaw, Poland; European Lab Non Linear Spect LENS, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy; Ist Nazl Ottica, Largo Fermi 6, I-50125 Florence, Italy.

Abstract: We carried out a joint experimental and theoretical investigation of the laser-induced anti-Stokes white emission (LIWE) observed in NdMnO3 nanocrystals. We evaluate numerically the mechanisms of the multiphoton ionisation, avalanche process, and the blackbody radiation, to provide a phenomenological model to interpret, and even predict, the LIWE phenomena. Through the theoretical modelling, photophysical and photoconductivity characterisations, we determine the ionisation rates (0.63-1.9 s-1), ionisation fraction of the Nd3+ + hv -> Nd4+ + e-, Mn3+ + hv -> Mn4+ + e-, and Mn2+ + hv -> Mn3+ + e-, from ionization energies similar to 0 until 52.58 eV, excitation at 808 and 975 nm, and different pressure conditions (10-6-103 mbar). We propose a mathematical description of the LIWE generation as a dynamical process that explains the supralinear dependence of the integrated intensity of the emission with the laser power density of excitation, pressure, as well, the photophysical kinetics in order of similar to ms to s, and the photocurrent (similar to nA) observed under excitation at high values of laser power density (similar to kW cm-2).

Journal/Review: JOURNAL OF MATERIALS CHEMISTRY C

More Information: This work was supported by the NCS project Grant No. NCN-2020/37/B/ST5/02399. The authors thank Dr Karolina Ledwa (INTiBS) for the TEM analysis and Dr Pawel Gluchowski (Graphene Energy/INTiBS) for preparing the ceramics analysed in this work. Talita J. S. Ramos acknowledges Prof. Dr Ricardo Luiz Longo (UFPE) for suggesting the interpretation of LIWE using equilibrium rate equations and also appreciates the fellowship support provided by the Next Generation EU project P2022ALSMP VISIO (CUP B53D23025290001).
KeyWords: Optical-absorption Intensities; Up-conversion; Induced Incandescence; Blackbody Emission; Lanthanide; Model; Ions; Photoluminescence; Ionization; Excitation
DOI: 10.1039/d5tc03387j