Luminescence Of Pr3 Research Articles

Structure and luminescence of Pr3+-doped oxyfluoride glass-ceramics containing Na5Y9F32: Pr3+ nanocrystals

Oxyfluoride glass-ceramics have become a focal point of recent research, positioned to advance significantly in areas such as LED illumination and optical data storage, etc. This study successfully prepared Pr3+-doped fluorosilicate glass and glass-ceramics embedded Na5Y9F32 nanocrystals. The introduction of Pr2O3 into the glass matrix disturbs the network structure, leading to a reduction in the band gap from 3.66 eV to 3.42 eV. When subjected to 443 nm light excitation, the 1.0 mol% Pr3+-doped glass-ceramics crystallized at 690 °C for 1.0 h exhibit the most potent luminescence, displaying seven emission peaks resulting from the radiative transition of Pr3+ ions, manifesting yellowish-pink hues. Furthermore, when stimulated by a 450 nm LD, the glass-ceramics display a distinct emission peak at approximately ∼247 nm, attributed to the electron transitions of 4f5d → 3H4 for Pr3+ ions. The luminescent properties of these glass-ceramics embedded with Na5Y9F32 nanocrystals illustrate potential applications in up-conversion and down-conversion luminescence.

Multi-Band Emission of Pr3+-Doped Ca3Al2O6 and the Effects of Charge Compensator Ions on Luminescence Properties.

Multi-band emission luminescence materials are of great significance owing to their extensive application in diverse fields. In this research, we successfully prepared a series of Pr3+-doped Ca3Al2O6 multi-band emission phosphors via a high-temperature solid-state method. The phase structure, morphology, luminescence spectra and decay curves were investigated in detail. The Ca3Al2O6:Pr3+ phosphors can absorb blue lights and emit lights in the 450-750 nm region, and typical emission bands are located at 488 nm (blue), 525-550 nm (green), 611-614 nm (red), 648 nm (red) and 733 nm (deep red). The influence of the Pr3+ doping concentration was discussed, and the optimal Pr3+ doping concentration was determined. The impacts of charge compensator ions (Li+, Na+, and K+) on the luminescence of Pr3+ were also investigated, and it was found that all the charge compensator ions contributed positively to the emission intensity. More importantly, the emission intensity of the as-prepared phosphors at 423 K can still maintain 65-70% of that at room temperature, and the potential application for pc-LED was investigated. The interesting results indicate that the prepared phosphors may serve multifunctional and advanced applications.

Multimodal luminescence in Pr3+ single-doped Li2CaSiO4 phosphor for optical information storage and anti-counterfeiting applications

Multimodal luminescence in Pr3+ single-doped Li2CaSiO4 phosphor for optical information storage and anti-counterfeiting applications

Experimental and theoretical studies on NIR luminescence of titanate‐germanate glasses doped with Pr3+ and Tm3+ ions

AbstractNear‐infrared (NIR) luminescence of Pr3+ and Tm3+ ions in titanate‐germanate glasses has been studied for laser and fiber amplifier applications. The effect of the molar ratio GeO2:TiO2 (from 5:1 to 1:5) on spectroscopic properties of glass systems was studied by absorption, luminescence measurements, and theoretical calculations using the Judd–Ofelt theory. It was found that independent of the TiO2 concentration, intense NIR emissions at 1.5 and 1.8 μm were observed for glasses doped with Pr3+ and Tm3+ ions, respectively. Moreover, several spectroscopic and NIR laser parameters for Pr3+ and Tm3+ ions, such as emission bandwidth, stimulated emission cross‐section, quantum efficiency, gain bandwidth, and figure of merit, were determined. The results were discussed in detail and compared to the different laser glasses. Systematic investigations indicate that Pr3+‐doped system with GeO2:TiO2 = 2:1 and Tm3+‐doped glass with GeO2:TiO2 = 1:2 present profit laser parameters and could be successfully applied to NIR lasers and broadband optical amplifiers.

Near-infrared quantum cutting luminescence in Pr3+/Yb3+ doped lead bismuth borate glass

In this paper, thermally stable lead-bismuth-borate glasses were doped with 0.5 mol% of Pr3+ ions at several concentration levels of Yb3+ ions. Structural characterizations were performed via Raman, differential scanning calorimetry, optical absorption and fluorescence spectra. The Judd–Ofelt intensity parameter, {Omega }_2, of Pr3+ doped glass was comparatively higher than those from reported ones, which reflects the increase of co-valency and asymmetry of chemical bonds in the local environment of Pr3+. Near-infrared emission in 900–2200 nm wavelength range was recorded through 443 nm blue laser pumping. Visible to near-IR quantum cutting and concentration quenching mechanisms were discussed to understand the luminescent behaviour. Intense IR emission (sim 1.0,upmu {text {m}}) features generated by absorbing one visible photon leads to quantum efficiencies close to 128% in Pr3+/Yb3+ co-doped samples which may improve the solar spectrum absorption and accordingly, increase the efficiency of c-Si solar cells. Emission cross-section, lifetime, figure of merit and gain bandwidth corresponding to Pr3+: ^3F_2 rightarrow ^3H_4 (sim 2.0,upmum) were comparatively reported suggesting that the glass with molar composition 0.5Pr3+/0.1Yb3+ might be a potential candidate for sim 2.0,upmum laser operation with low pump threshold.

Strain Modulation for High Brightness Blue Luminescence of Pr3+-Doped Perovskite Nanocrystals via Siloxane Passivation

Strain Modulation for High Brightness Blue Luminescence of Pr³⁺-Doped Perovskite Nanocrystals via Siloxane Passivation

Synthesis and luminescence of Pr3+-doped Lu2MoO6 and Y2MoO6 phosphors for white light-emitting diodes

Synthesis and luminescence of Pr3+-doped Lu2MoO6 and Y2MoO6 phosphors for white light-emitting diodes

Comparison of co-operative down-conversion luminescence in Pr3+, Yb3+ doped CaF2 and SrF2

An optical study of the down conversion luminescence in Pr (0.5 mol%), Yb (1 mol%) doped CaF2 and SrF2 synthesized by high temperature Solid state reaction method has been done. The down-conversion luminescence intensities of both the hosts have also been compared to identify which is better in terms of optical properties. The photoluminescence excitation and emission were investigated under visible excitation at 445 nm. Besides optical characterization, magnetic properties were also investigated to quantify their magnetic behavior and their comparison. In the present case, the luminescence intensity is higher for SrF2: Pr,Yb and the detailed mechanism behind this has also been discussed. The study highlights the potential of Pr,Yb doped SrF2 and CaF2 for various optical and optoelectronic applications.

Photoluminescence and afterglow behavior of orange-reddish Pr3+-activated Sr3Al2O6 phosphor

The orange-reddish Sr3Al2O6:Pr3+ samples were prepared using solid state reaction in air and the photoluminescence properties of the phosphors were investigated. The as-prepared phosphors were studied systematically by X-ray diffraction, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS), photoluminescence (PL) spectra, afterglow decay curves, thermoluminescence (TL) glow spectra, X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR). The luminescence of Pr3+-activated Sr3Al2O6 exhibited a strong emission peak at 611 ​nm under 246 ​nm excitation arising from the intrinsic f-f transition of Pr3+ as an emitting centre. The ions of Pr3+ acted as not only the activators but also the providers of traps. The doping concentration of Pr3+ has a significant effect on the photoluminescence and long afterglow luminescence. The TL process and possible luminescence working mechanism of the Sr3Al2O6:Pr3+ were discussed in detail. The suitable and effective trap depths as well as the high concentration of defects for Sr3Al2O6 phosphors were obtained though the introduction of Pr3+ ions, greatly extending the lifespan of the electron-hole pair in the lattices for the improvement of the luminescent properties of Sr3Al2O6 long afterglow phosphors.

Спектрально-люминесцентные свойства тербийсодержащих циркономолибдатов

К настоящему времени всесторонне изучены двойные молибдаты одно- и четырёхвалентных элементов, достаточно полно исследованы системы с молибдатами одно- и трёхвалентных элементов. Некоторые материалы на основе двойных молибдатов, например, содержащие лантаниды, являются перспективными для лазерной техники и электроники. Между тем, сведения о свойствах, особенно оптических, у молибдатов, содержащих редкоземельные элементы и цирконий, ограничены. Целью данной работы являлось исследование люминесцентных свойств самоактивированных тербийсодержащих циркономолибдатов составов Tb2Zr3(MoO4)9 (1:3) и Tb2Zr(MoO4)5 (1:1),кристаллизующихся в двух разных структурных типах.Порошковые образцы исследуемых молибдатов синтезированы керамической технологией. В работе использованы методы измерения спектров поглощения, возбуждения и люминесценции с помощью спектрофотометра Perkin Elmer Lambda 950. Люминесценция возбуждалась ксеноновой лампой ДКСШ-250 мощностью 250 Вт через монохроматор МДР-2 и регистрировалась с помощью двойного монохроматора СДЛ-1 с решеткой 600 штрихов/мм. В работе исследованы оптические свойства новых циркономолибдатов, содержащих ионы Tb3+. В них обнаружена яркая люминесценция в зелёной области спектра, обусловленная переходами внутри 4f- оболочки редкоземельного иона Tb3+, возбуждающегося как в полосах, связанных с 4f–4f переходами, так и в полосе с переносом заряда.Идентифицированы наблюдаемые спектральные линии и полосы люминесценции и возбуждения.Показано, что положение широкой полосы возбуждения, связанное с переходами «с переносом заряда» от O2– в группах MoO4 2– через связи Mo–O к люминесцентным центрам (Tb3+), не зависит от структуры матрицы. Структура и интенсивность наблюдаемых спектральных линий, свидетельствующие о низкой симметрии кристаллического окружения Tb3+, коррелируют с данными структурного анализа. Полученные в работе результаты могут быть использованы при создании перспективных люминофоров в зеленой области спектра при ультрафиолетовомвозбуждении.
 
 
 
 
 ЛИТЕРАТУРА
 1. Софич Д. О., Доржиева С. Г., Чимитова О. Д., Базаров Б. Г., Тушинова Ю. Л., Базарова Ж. Г., Шендрик Р. Ю. Гиперчувствительный переход 5D0−7F2 трехвалентного европия в двойных молибдатах.Изв. РАН, Сер. физич. 2019;83(3): 384–387. DOI: https://doi.org/10.1134/S03676765190302202. Sofi ch D., Tushinova Yu. L., Shendrik R., Bazarov B. G., Dorzhieva S. G., Chimitova O. D., BazarovaJ. G. Optical spectroscopy of molybdates with composition Ln2Zr3(MoO4)9 (Ln: Eu, Tb). Opt. Mater. 2018;81:71–77. DOI: https://doi.org/10.1016/j.optmat.2018.05.0283. Софич Д., Доржиева С. Г., Чимитова О. Д., Базаров Б. Г., Ю.Л. Тушинова Ю. Л., Базарова Ж. Г.,Шендрик Р. Ю. Люминесценция ионов Pr3+ и Nd3+ в двойных молибдатах. ФТТ. 2019;61(5): 943–945.DOI: https://doi.org/10.21883/FTT.2019.05.47598.35F4. Доржиева С. Г., Тушинова Ю. Л., Базаров Б. Г., Непомнящих А. И., Шендрик Р. Ю, Базарова Ж. Г.Люминесценция Ln-Zr-содержащих молибдатов. Изв. РАН. Сер. физич. 2015;79(2): 300–303.DOI: https://doi.org/10.7868/S03676765150200765. Baur F., Justel Th. New red-emitting phosphor La2Zr3(MoO4)9:Eu3+ and the infl uence of host absorptionon its luminescence effi ciency. Aust. J. Chem. 2015;68(11): 1727–1734. DOI: https://doi.org/10.1071/CH152686. Qi S., Huang Y., Cheng H., Seo H. J. Luminescence and application of red-emitting phosphors of Eu3+-activated R2Zr3(MoO4)9 (R = La, Sm, Gd). Electron. Mater. Lett. 2016;12(1): 171–177. DOI: https://doi.org/10.1007/s13391-015-5244-17. Базарова Ж. Г., Тушинова Ю. Л., Базаров Б. Г., Доржиева С. Г. Двойные молибдаты редкоземель-ных элементов и циркония. Изв. АН. Сер. химич. 2017;(4): 587–592. Режим доступа: https://elibrary.ru/item.asp?id=291126318. Клевцова Р. Ф., Солодовников С. Ф., Тушинова Ю. Л., Базаров Б. Г., Глинская Л. А., Базарова Ж. Г.Новый тип смешанного каркаса в кристаллической структуре двойного молибдата Nd2Zr3(MoO4)9. ЖСХ. 2000;41(2): 343–348. Режим доступа: https://jsc.niic.nsc.ru/article/15321/9. Базаров Б. Г., Гроссман В. Г., Клевцова Р. Ф., Аншиц А. Г., Верещагина Т. А., Глинская Л. А., Тушинова Ю. Л., Федоров К. Н., Базарова Ж. Г. Кристаллическая структура двойного молибдатаPr2Hf3(MoO4)9. ЖСХ. 2009;50(3): 567–571. режим доступа: https://www.sibran.ru/upload/iblock/a76/a769f642103101e559f4b38d5805319e.pdf10. Grossman V. G., Bazarov B. G., Bazarova T. T., Bazarova J. G., Glinskaya L. A., Temuujin J. Phaseequilibria in the Tl2MoO4 – Ho2(MoO4)3 – Zr(MoO4)2 system and the crystal structure of Ho2Zr2(MoO4)7 andTlHoZr0.5(MoO4)4. J. Ceram. Process. Research. 2017;18(12): 875–881.11. Bazarov B. G., Bazarova J. G., Tushinova Y. L., Solovyov L. A., Dorzhieva S. G., Surenjav E., TemuujinJ. A new double molybdate of erbium and zirconium, its crystalline structure and properties. J. AlloysCompd. 2017;701: 750–753. DOI: https://doi.org/10.1016/j.jallcom.2017.01.17312. Bunuel M. A., Lozano L., Chaminade J. P., Moine B., Jacquier B. Optical properties of Tb3+-dopedRb2KInF6 elpasolite. Opt. Mater. 1999;13(2): 211–223.DOI: https://doi.org/10.1016/S0925-3467(98)00085-813. Gupta S. K., Ghosh P. S., Yadav A. K., Pathak N., Arya A., Jha S. N., Bhattacharyya D., Kadam R. M.Luminescence properties of SrZrO3/Tb3+ perovskite: host-dopant energytransfer dynamics and local structure of Tb3+. Inorg. Сhem. 2016;55(4): 1728–1740. DOI:https://doi.org/10.1021/acs.inorgchem.5b02639

Temperature-dependent upconversion luminescence in ferroelectric 1.5%Pr/3%Yb:0.75Pb(Mg1/3Nb2/3)O3–0.25PbTiO3 transparent ceramics for non-contact thermometry and optical heating

Non-contact optical thermometry based upon fluorescence intensity ratio (FIR) has attracted much attention because of its excellent accuracy and sensitivity. Recently we reported the upconversion luminescence in Pr3+/Yb3+ co-doped 0.75Pb(Mg1/3Nb2/3)O3–0.25PbTiO3 transparent ceramics [Z. Lv et al., Ceramics International 45 (2019) 10924–10929]. In this article we study the temperature dependence of upconversion emissions from the 1.5%Pr/3%Yb:0.75Pb(Mg1/3Nb2/3)O3–0.25PbTiO3 transparent ceramics. The FIR between the 1D2-3H4 and 3P0–3H4 emissions fits a thermally coupled-levels-like equation, and exhibits the maximum relative sensitivity of 1.03% K−1 at the temperature 320 K. Meanwhile, the FIRs of IRed/IGreen, IRed/IBlue and IRed/IBG show linear responses versus temperature and illustrate the high constant sensitivities of 1.09%–2.9% K−1, but in a narrow temperature range of 140–240 K. The multiple temperature-sensing performances offer us chances to select distinct response functions on the basis of the practical demands. In addition, laser induced heating was observed in the transparent ceramics. The generated temperature in the ceramics can be accurately monitored and regulated from 329 to 377 K by changing the excitation power from 1.58 to 8.61 W/cm2. The high heating efficiency of ~6.83 K cm2/W makes the transparent ceramics suitable for optical heater. The transparent ceramics exhibit excellent piezoelectric and ferroelectric performances, and thus they are promising candidates for multifunctional optical-electro devices besides non-contact thermometer and optical heater.

Spectroscopic investigations on Yb3+ doped and Pr3+/Yb3+ codoped tellurite glasses for photonic applications

In this work, we report on structural and spectroscopic properties of Yb3+ doped and Pr3+/Yb3+ co-doped TeO2-Bi2O3-ZnO-Li2O-Nb2O5 (TBZLN) tellurite glasses. Bending and stretching modes of TeO2 and Te–OH bond (strong and weak) were analysed from the deconvolution of observed Raman and FT-IR spectra. Based on the absorption measurements, the energy bands of Yb3+ and Pr3+ ions are assigned. The spectroscopic properties for the radiative transitions of Yb3+ and Pr3+ ions were reported using McCumber and Judd-Ofelt theories. Visible emission bands originating from 3P1 and 3P0 to lower lying levels of Pr3+ were registered under 447 nm excitation. The emission band around 1334 nm assigned to the Pr3: 1G4→3H5 was observed when excited at 980 nm. The stimulated emission cross-section (σemi(λ)) and effective linewidth (Δλeff) for the 3P1→3H6, 3P1→3H5, 3P0→3H6, 3P0→3F2, 3P1→3F3, 3P1→3F4, 3P0→3F4 and 1G4→3H5 transitions of Pr3+ are reported. Upconversion luminescence in Pr3+/Yb3+ co-doped glass upon 980 nm excitation was measured. Possible resonant transfer processes between Yb3+ and Pr3+ ions are presented and discussed. The chromaticity co-ordinates were also evaluated from the visible emission spectra showing that Pr3+/Yb3+ co-doped glass may be suitable for the development of yellow-orange (λexc = 447 nm) and near white light (λexc = 980 nm) emitting devices in photonics.

Luminescence of Pr3+ Impurity Centers and Defects in Sr9Sc (PO4)7:Pr3+

The spectroscopic characteristics and luminescence decay kinetics of Sr9Sc(PO4)7:Pr3+(1%) were investigated using synchrotron radiation of ultraviolet (UV), vacuum ultraviolet (VUV) and X-ray ranges, as well as pulsed cathodoluminescence (PCL) methods at temperatures of 10, 90, and 295 K. The luminescence spectra contain three groups of bands and lines. In the UV range, the observed bands correspond to interconfigurational 5d → 4f transitions in Pr3+ ions. In the visible spectrum, the wide luminescence band of defects dominates, as well as narrow lines associated with intraconfigurational 4f → 4f transitions in Pr3+ ions. When excited by an electron beam (5 Hz), the main component with a decay time τ ∼ 17 ns dominates in the decay kinetics of the 5d → 4f luminescence. The decay kinetics of 5d → 4f luminescence upon excitation with high-frequency (τ ∼ 8 MHz) synchrotron radiation of the X-ray range contains a fast component (τ ∼ 15 ns) against the background of the slow component of the μs-range. An effective nonradiative energy transfer is observed from impurity centers to defects, as well as from the host to Pr3+ ions and defects.

Luminescence of Pr3+ and Nd3+ Ions in Double Molybdates

The optical spectra of samples of double zirconium molybdates activated by rare-earth Pr3+ and Nd3+ ions are studied. The presence of bands corresponding to the 4f–4f transitions of Pr3+ and Nd3+ trivalent ions in the absorption, excitation, and luminescence spectra is shown. A strong dependence of the luminescence intensity of Pr3+ ions on temperature is revealed.

Lanthanide doped bismuth tungstates: an investigation for LED and photocatalysis applications

In this work, we studied optical, photocatalytic and photoelectrochemical properties of a series of lanthanide-doped double layered Aurivillius type bismuthoxides. The visible-light harvesting photocatalysts doped with Eu, Pr, Nd, Tm, Ho and Ceions were synthesized by solid-state synthesis method using lanthanide precursors ranging from 0.2 to 10 mol % and were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Furthermore, luminescence of Pr and Euion doped catalysts are evaluated. Photoelectrochemical behaviour of the powders was also investigated. Best photoelectrochemical response is achieved with Tm ion doped sample.

Effect of High Pressure in the Luminescence of Pr3+-Doped Ge2O–PbO Glass Containing Au Nanoparticles

In this paper, the combined effect of gold nanoparticles and high-pressure densification on the luminescence of Pr3+-doped heavy metal GeO2–PbO photonic glass was investigated. Localized states related to ion-trapped exciton defects, S1 and S2, were observed at 342 and 412 nm before densification. After densification under 7.7 GPa, the structure of the glass host changed irreversibly, as indicated by the infrared spectrum, refractive index, and density measurements. Transmission electron microscopy analyses indicated that the high-pressure densification induced the formation of clusters of gold nanoparticles. The modifications observed in the absorption and luminescence spectra of Pr3+ ions in the VIS–NIR range were associated to the changes in the local field surrounding the Pr3+ ions in the host glass induced by high pressure. For excitation at 445 nm (luminescence from 3P2) and 593 nm (luminescence from 1D2), the combined effect of densification and gold nanoparticles induced an increase in the emissio...

Synthesis and luminescence of Pr3+ doped Lu2MoO6 phosphors

A series of Pr3+ doped Lu2MoO6 phosphors were synthesized by a solid state reaction. The phase and optical properties of the synthesized phosphors were investigated. The XRD patterns indicate that the synthesized phosphors have a monoclinic structure and the doped Pr3+ ions have no influence on the phase structure of Lu2MoO6 host. Pr3+ doped Lu2MoO6 phosphors contain a broad excitation band originating from the O2- → Mo6+ charge transfer transitions and several weak excitation bands resulting from 3H4 → 3Pj (j = 2, 1, 0) transitions of Pr3+. Under the excitation at 365 nm, Pr3+ doped Lu2MoO6 phosphors show emission bands ranging from blue to red region. The emission and decay characteristics of Pr3+ doped Lu2MoO6 phosphors indicate the energy transfer from Lu2MoO6 host to doped Pr3+ ions. Lu1.92Pr0.08MoO6 phosphor emits warm white light with the CIE coordinates of (0.352, 0.316) and the CCT value of 4499 K.

Site distortion in Li2SrSiO4: Influence on Pr3+ emission and application in wLED

Luminescence of Pr3+ in Li2SrSiO4 showed a broader f–f emission band compared with YAG:Pr3+. Atom parameters of Li2SrSiO4 crystal were refined to provide data for quantifying the distortion of [SrO8] polyhedron. The distortion of [SrO8] was compared with that of [YO8] polyhedron in YAG to show the different Pr3+ environments in Li2SrSiO4 and YAG. Then, Pr3+ was co-doped with Eu2+ in Li2SrSiO4 to provide a single phosphor for wLEDs. Energy transfer processes from 5d of Eu2+ to both 3P2 and 1D2 of Pr3+ were observed. The interaction type between Eu2+–Pr3+ was proved to be dipole-quadrupole and kinetics of the energy transfer process was discussed based on Inokuti–Hirayama model.

Luminescence properties of calcium tungstate activated by lanthanide(III) ions

Calcium tungstate phosphors activated by the Ln3+ ions (Ln=Pr, Nd, Tb, Yb) were synthesized by a traditional high-temperature solid-state method. The crystal structures and morphologies of the products were characterized by scanning electron microscopy (SEM), X-ray powders diffraction (XRD) and infrared spectra (FT-IR). The samples were found to show luminescence properties (down-conversion, DC, at excitation wavelength 254 nm and up-conversion, UC, at excitation wavelength 980 nm). CaWO4 doped with Tb3+/Yb3+ showed green DC and UC luminescence characteristic of Tb(III) ion in the range of 470–660 nm, corresponding to the 5D4→7F6,5,4,3,2 electronic transition. CaWO4 doped with Pr3+/Yb3+ showed week blue, green and red (DC and UC) luminescence of Pr(III) ion, in the wavelength region of 450–700 nm. Emission peaks were ascribed to the 3P1→3H4,5,6, 3P0→3H4,5,6, 3P1→3F2 and 3P0→3F2 transitions, respectively. CaWO4 doped with Nd3+/Yb3+ phosphor emitted orange UC luminescence at 450–690 nm (2P3/2→4I15/2, 4G7/2→4I9/2,11/2,13/2) and strong near-infrared UC luminescence at 720–900 nm (4F7/2+4S3/2→4I9/2, 4F5/2+2H3/2→4I9/2, 4F3/2→4I9/2) which is the characteristic of Nd(III) ion.

Photo-electronic properties and persistent luminescence in Pr3+ doped (Ca,Sr)TiO3 ceramics

We obtained direct evidence of intervalence charge transfer (IVCT) in Ca1−xSrxTiO3:Pr3+ (x=0, 0.3, 0.5, 0.8, and 1) by a photocurrent excitation (PCE) measurement, and proposed a mechanism of the persistent luminescence based on the results of the PCE and persistent luminescence measurements. The PCE spectra in all samples showed two bands in the UV range due to the band-to-band and IVCT transitions. With increasing Sr content, x, the host bandgap energy decreased monotonically from 3.59 to 3.23eV, and the IVCT energy increased from 3.20 to 3.38eV. PCE bands of the Pr3+:3H4→3PJ transitions in the blue region were observed only in the samples with x=0, 0.3, and 0.5 and the relative intensity decreased with increasing Sr content, x. Based on temperature dependence of the PCE results in the sample with x=0, a thermally assisted photoionization process was indicated under the 3H4→3PJ excitation. Red persistent luminescence was observed in the samples with x=0, 0.3 and 0.5, showing trap depth in the range of 0.48–0.35eV, which was estimated from the thermoluminescence measurement. The afterglow process by the electron moving through the conduction band was evidenced by the similar quenching behavior of the 3H4→3PJ band both in the PCE and afterglow excitation spectra. The difference in the processes of persistent luminescence among the band-to-band, IVCT and 3H4→3PJ excitations was discussed.