Cooperative luminescence of Yb3+ ions in multisite YAM crystal

• Published in: Journal of luminescence 2024-01, Vol.265, p.120162, Article 120162
• Main Authors: Kaczkan, M., Malinowski, M., Suchocki, A., Turczyński, S.
• Format: Article
• Language: English
• Subjects: Cooperative luminescence; Site selective spectroscopy; Y4Al2O9; Yb3+ photoluminescence
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2023.120162

A series of Yb3+-doped yttrium aluminum monoclinic Y4Al2O9 (Yb:YAM) single crystals with Yb3+ ion concentrations of 0.1, 1, 5 and 10 at.% was grown by means of micro pulling down method. Blue emission was observed in Yb3+ activated YAM crystals under infrared site-selective laser excitation. Through the excitation and emission spectra, decay time measurements and excitation intensity dependence the process responsible for this anti-Stokes emission was assigned to the cooperative deexcitation of two Yb3+ ions. The results show that at 10% Yb3+ dopant concentration investigated system could be considered as single-site system in which cooperative luminescence is dominated by the energetically lowest Yb3+ site. Theoretical cooperative emission spectrum and the cooperative luminescence rate of Yb3+:YAM were calculated. •Yb3+ doped Y4Al2O9 (YAM) crystals were fabricated by micro pulling down method.•Cooperative luminescence (CL) of Yb3+ pairs was observed in Yb:YAM crystals.•Decay time of cooperative luminescence decreased with increasing Yb3+ concentration.•In 10%Yb:YAM CL is dominated by the energetically lowest Yb3+ site.