Nanooptics and photonics

Localized exciton luminescence of the RVO4:Bi3+ (R =Y, Gd, Lu)
V. Tsiumra1,2, A. Krasnikov3, S. Zazubovich3, L. Vasylechko4, A. Voloshinovskii2, Ya. Zhydachevskyy1,4, A. Suchocki1,5
1 Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, 02-668, Poland
E-mail: tsiumra@ifpan.edu.pl
2 Ivan Franko National University of Lviv, Kyryla and Mefodiya 8a, Lviv 79005, Ukraine
3 Institute of Physics, University of Tartu, W. Ostwaldi 1, 50411, Tartu, Estonia
4 Lviv Polytechnic National University, 12 Bandera, Lviv 79646, Ukraine
5 Institute of Physics, Kazimierz Wielki University, Weyssenhoffa 11, 85-072, Bydgoszcz, Poland

The Bi3+–doped rare earth orthovanadates where a trivalent Bi3+ ion substitutes for a trivalent rare-earth ion are considered as prospective phosphors due relatively high quantum yield of their photoluminescence in occurred in visible range. Despite the considerable interest to RVO4:Bi3+ (R = Y, Gd, Lu) the nature of their visible emission remains controversial. Recent studies indicate that the excited 3P1 state of Bi3+ ion in YVO4 is located inside the conduction band.
In the present work, the localized exciton model of the photoluminescence of the studied materials is exploited. Namely, a hole localized on the Bi3+ ion and an electron on the V5+ ion with formation of the Bi3+-V5+ state is proposed for explanation of the RVO4:Bi3+ luminescent properties. To confirm the model, theoretical calculations of the energy band structure are combined with steady-state and time-resolved photoluminescence studies as well as photoluminescence decay measurements in the temperature range from 4.5 to 500 K.