Pressure effect on luminescence dynamics in Pr³⁺-doped LiNbO₃and LiTaO₃crystals

Abstract

The 1 D 2 → 3 H 4 luminescence kinetics of LiNbO 3 :Pr 3+ and LiTaO 3 :Pr 3+ have been measured under high hydrostatic pressure applied in a diamond anvil cell for pressures up to 200 kbar. The luminescence decays have been analysed using the continuous function decay times distribution. Two mechanisms that accelerate the emission decays with increasing pressure have been proposed: the non-radiative depopulation of the 1 D 2 state through the Pr 3+ trapped exciton, dominating in LiNbO 3 :Pr 3+ and pressure-induced increase of the 1 D 2 → 3 H 4 transition probability, dominating in LiTaO 3 :Pr 3+ .

Luminescence of Ca(NbO3)2:Pr3+ at ambient and high hydrostatic pressure

“…[8], the decay time of the 1 D 2 emission upon blue excitation was reported to be 59 ms; this discrepancy can be explained by the fact that in the sample investigated by Macalik et al [8] the Pr 3+ concentration was lower than for the present one (0.5 at% instead of 1.0 at%), and the luminescence from the 1 D 2 level is significantly affected by concentration quenching [12]. A short value (o1 ms) was also found by Macalik et al [8] for the decay time of the 3 P 0 state; the fast decay of this level perfectly agrees with a depopulation mechanism due to a crossover to a Pr 3+ -trapped exciton state as it has been observed in LiTaO 3 :Pr 3+ [13].…”

“…The decrease in intensity of the 3 P 0 -3 F 2 and 3 P 0 -3 H 4 emission transitions under high pressure, accompanied by a significant shortening of the luminescence decay time, is attributed to the increasing probability of nonradiative depopula- tion of the 3 P 0 state towards a Pr 3+ -trapped exciton. The observed behavior is very similar to the case of LiTaO 3 :Pr 3+ , where the 3 P 0 -3 H 4 emission is partly quenched by nonradiative processes via a Pr 3+ -trapped exciton [13], and is attributed to the decreasing energy of the Pr 3+ -trapped exciton with increasing pressure. This depopulation also occurs in the case of the 1 D 2 state, but is much less evident due to the lower energy of this level, compared to 3 P 0 .…”

“…Above 33 kbar, the emission is too weak to allow a meaningful analysis of the decay curve. A very similar effect has been observed in the case of LiTaO 3 :Pr 3+ , where the quenching of the 3 P 0 -3 H 4 emission intensity was related to nonradiative depopulation of the 3 P 0 state via a Pr 3+ -trapped exciton, [13]. The acceleration of this effect with increasing pressure was attributed to pressureinduced decreasing of the energy of the Pr 3+ -trapped exciton, derived from the increasing of Pr 3+ ionization energy (Pr 3+ -Pr 4+ transition) [13].…”

Pressure evolution of luminescence in Sr Ba1−(NbO2)3:Pr3+ (x=1/2 and 1/3)

“…In contrast to this effect, when SBN:Pr 3 þ is excited by the internal 3 H 4 -3 P J transitions the emission spectrum is dominated by 3 P 0 luminescence [11]. A case when Pr 3 þ emission was dependent on the excitation wavelength has been also observed in Pr 3 þ doped LiTaO 3 [12,13] and LiNbO 3 [13,14] and has been attributed to the de-excitation of the system through praseodymium trapped exciton (PTE). To consider the interaction between the Pr 3 þ and host in SBN:Pr 3 þ , we investigated Pr 3 þ luminescence as a function of hydrostatic pressure.…”

Luminescence properties of Eu3+- and Mg2+-doped LiTaO3 obtained via the polymeric precursor method

“…In the literature several studies have been published about LiTaO 3 doped with different RE ions-among them Pr 3+ [9,10], Er 3+ [11], Tb 3+ [12]. This work considers the effect of the simultaneous addition of europium and magnesium into LiTaO 3 and their correlation with the strength of metal-oxygen bonding and with the generated lithium vacancies.…”