1. Introduction

Compared with the current application of organic optical storage materials (such as cyanine dyes and phthalo cyanine dyes) the more stable inorganic persistent luminescence materials, also called electron trapping materials, have attracted more and more attention in the fields of optical information storage which are also called photo-stimulated luminescence materials (PSLs) [1–12], besides as vivo bio-imaging [13–19] and alternating current-light emitting diodes materials [20,21]. The reason why PSLs were considered as candidates of optical storage materials is their capability of realizing “write-in” and “read-out” of optical information, while, the “write-in” and “read-out” ability is closely related to emitting centers and trap centers in PSLs materials [22–26]. In principle, the emitting centers come from luminescent ions, which can be intrinsic or doped ions, and are responsible for the optical information “write-in” under excitation of UV or visible light, nevertheless, the traps originated from “defects” or “extra energy band level” act as a key role in “read-out” of optical information upon long-wave photo-stimulation by releasing the captured charge carriers in the traps. Therefore, the capability that optical information can be cyclically read-out strongly depends on the trap concentration and trap depth in PSLs. However, ideal PSLs with abundant and controlled deep traps are scarce, because the trap tailoring in PSLs is still a challenging and difficult task. Up to now, a doping or co-doping strategy is frequently applied to modulate trap properties in PSLs, as reported in some researches on single-doped Ca₃Ga₄O₉:Bi³⁺ [5], double-doped Y₃Al₂Ga₃O₁₂:Ce³⁺, Cr³⁺ [27] and BaSi₂O₅:Eu²⁺,Nd³⁺ [22], and even four-doped Ba₂SiO₄:Eu²⁺,Tm³⁺,Ho³⁺,Dy³⁺ [6]. As an example of Ba₂SiO₄ matrix, compared to single doping Ba₂SiO₄:Eu²⁺ phosphors, after co-doping, triple-doping, and four-doping, these phosphors presented that more traps were created and the trap depth was deepened. Especially, the four-doping Ba₂SiO₄:Eu²⁺,Tm³⁺,Ho³⁺,Dy³⁺ phosphors showed rich isolated traps and the related traps depth is 0.723 eV, 0.841 eV, and 1.02 eV, respectively [6]. On the basis of doping strategy, further modulating trap properties by annealing treatment in different atmospheres is rarely reported.

In our research work, a kind of Ce³⁺ and V³⁺ co-doped (LuYGd)(Al₄Ga)O₁₂ (LYGAGGCV-0) yttrium aluminum gallate garnet was synthesized in air, while the original matrix is the well-known A₃B₅O₁₂ (YAG Garnet) with elements substitutions at A and B sites. Then some LYGAGGCV-0 phosphors were further annealed in both air atmosphere and a weak reducing atmosphere, obtained LYGAGGCV-1 and LYGAGGCV-2 phosphors, respectively. Compared to LYGAGGCV-1 phosphors, an oxygen deficient environment easily formed profuse oxygen vacancies in LYGAGGCV-2 phosphors, which could largely promote to add trap concentration and deepen trap depth, to some extent. This obvious superiority has been proved by thermoluminescence spectra (TL) measurement results, and the total TL intensity of LYGAGGCV-2 is about 7.46 times that of LYGAGGCV-0. Moreover, the TL peaks of LYGAGGCV-2 shift to higher temperature range.

2. Experiments

It has been reported that the optimal concentration of co-dopants Ce³⁺ and V³⁺ in yttrium aluminum gallate garnet phosphors was 0.015 mol and 0.002 mol, respectively [24]. In our experiments, referring to this, a starting chemical composition of phosphor (LuY_0.985Gd)(Al_3.998Ga)O₁₂:0.015Ce³⁺,0.002V³⁺ (simply named as LYGAGGCV-0) was synthesized at 1550 °C for 6 h by solid-state reaction method in air, with Lu₂O₃ (99.99%), Y₂O₃ (99.99%), Gd₂O₃ (99.95%), Al₂O₃ (99.99%), Ga₂O₃ (99.999%), CeO₂ (99.99%), and V₂O₅ (99.6%) as raw materials. Then parts of LYGAGGCV-0 phosphors were annealed at 1000 °C for 6 h in air atmosphere, which is abbreviated as LYGAGGCV-1. While LYGAGGCV-2 phosphors were obtained after some of LYGAGGCV-0 phosphors were annealed at 1000 °C for 6 h in a weak reducing atmosphere (Ar:H₂=95:5, simply RA) with a gas flow rate of 1 L/min, to compare atmosphere influence on properties.

Furthermore, to demonstrate the optical information storage (OIS) capability, the phosphor films are required and fabricated. The LYGAGGCV-2 phosphors with better OIS properties were selected and mixed with silica gel precursors and cyclohexane in a weight ratio of 1:2:3, and then stirred for 1 h and sonicated for 1 h to form homogeneous viscous slurries. The phosphor slurries were casted on an aluminum plate to fabricate a flat precursor film. After heating at 45 °C for 0.5 h to remove air bubbles and heating at 60 °C for 2 h to cure, a flexible phosphor film was fabricated and its size and thickness is about 2.7 cm × 3.9 cm and 1.1 mm respectively.

Phase and crystal structure of phosphors were characterized by a Bruker D8 Advance X-ray diffractometer (XRD) with Cu Kα radiation at an interval of 0.02° in a 2θ range from 10° to 80°. Photoluminescence (PL) spectra, photoluminescence excitation (PLE) spectra, and PSL spectra were recorded by a fluorescence spectrophotometer (Hitachi Model F-4600, Xe lamp as light source, 150 W). Before PSL measurement, the phosphors were irradiated for 100 s by a Hg lamp of 254 nm wavelength (6 W), then removing the excitation source for 5 min, and finally the phosphors were excited again by a light of 808 nm using a fluorescence spectrophotometer. A heating stage (TAP-02) was used to monitor the temperature-dependent PL spectra. Fluorescence quantum yield (QY) was recorded by an Edinburgh spectrometer (FLS1000) equipped with an integrating-sphere at room temperature (RT). Electron paramagnetic resonance (EPR) at 77 K was measured by Bruker A300 X-band (9.85 GHz). The time-dependent and temperature-dependent TL curves were measured from RT to 773 K (500 °C) at a heating rate of 0.5 K/s, using a SL08 TL spectrometer (Radiation Science and Technology Co. Ltd, Guangzhou, China). And detection was with a photomultiplier tube (PMT; CR105, Beijing Hamamatsu, China), whose spectral response range was 300-650 nm. The PMT applied voltage was fixed at 500 V. Before all TL curves measured except temperature-dependent TL, phosphors were first irradiated by the light source built in the instrument. And the temperature-dependent TL curves were recorded after phosphors excited by a 365 nm Hg lamp (6 W) for 100 s, with a constant temperature electric heating stage (DB-1A, Changzhou Zhengrong Instrument Co., Ltd.). For the information optical storage demonstration, a laser source of 405 nm was applied as excitation.

3. Results and discussions

3.1 Crystal structure and luminescence properties

Figure 1 shows the XRD patterns of LYGAGGCV-0, LYGAGGCV-1, and LYGAGGCV-2 phosphors of (LuYGd)(Al₄Ga)O₁₂:Ce,V experienced calcination at 1550 °C in air, annealing at 1000 °C in air, and annealing at 1000 °C in reductive atmosphere (RA), respectively. Main diffraction peaks of these three samples all well match the relative diffraction peaks of the standard pattern of YAGG phase (Y₃Al₄GaO₁₂, JCPDS No. 89-6658) host. After bigger Gd³⁺ ions (1.042 Å) partly occupied Y³⁺ (1.019 Å) sites and smaller Lu³⁺ ions (0.976 Å) partly occupied Y³⁺ (1.019 Å) sites [28], the ionic radius difference between Lu³⁺ and Y³⁺ is about twice that of between Gd³⁺ and Y³⁺, resulting in the reducing of interplanar distance and shrinking of cell unit. Additionally, the XRD results show that annealing atmospheres have no obvious effect on main crystal phase composition of resultant phosphors, except for a little unreacted Lu₂O₃ and Al₂O₃ of raw materials as impurity without negative influence on luminescence of phosphors.

 

Fig. 1. (a) XRD patterns of LYGAGGCV-0 without annealing, LYGAGGCV-1 annealed in air, LYGAGGCV-2 annealed in RA, and the standard pattern of Y₃Al₄GaO₁₂ (JCPDS No. 89-6658).

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Figure 2 depicts the PLE and PL spectra of LYGAGGCV-0, LYGAGGCV-1 and LYGAGGCV-2 phosphors. Monitored at 500 nm, two broad PLE bands are in the range from 325 nm to 375 nm and from 390 nm to 480 nm, assigned to 4f→5d₂ and 4f→5d₁ transition of typical trivalent Ce³⁺, respectively [24,27,29]. Compared with Y₃Al₄GaO₁₂:Ce³⁺,V³⁺ reported by Li et al. [24], in our measurements, the PLE band from 4f→5d₂ transition shows a red-shift, whereas the band from 4f→5d₁ exhibits a blue-shift, owing to the substitution of smaller Lu³⁺ and bigger Gd³⁺ for Y³⁺. This result indicates that the 5d₂ excited state of Ce³⁺ moves towards a lower energy level, while the 5d₁ excited state moves towards a higher energy level, that is, the level splitting between the 5d₁ and 5d₂ excited states of Ce³⁺ increases. This is mainly because the ion radius difference between Lu³⁺ ion and Y³⁺ ion is about twice than that between Gd³⁺ ion and Y³⁺ ion, leading to the shrinkage of unite cell and dominant crystal field enhancement and thus intensifying the energy level splitting. Furthermore, the annealing atmosphere has no effect on the emission peak position and there still shows a typical Ce³⁺ dipole peak in a broad 460-650 nm range excited by a light of 450 nm. These three phosphors give only one strong emission peak at about 500 nm, assigned to 5d₁→4f transition of trivalent Ce³⁺ [24,27,29], emitting cyan light (Fig. 2(a)). Because the annealing treatment in air or in RA can increase the concentration of traps with deeper trap depth, especially for the sample LYGAGGCV-2 annealed in RA. When the excitation light irradiates phosphors, the excited electrons in the ground states jump to the excited states, a part of photoluminescent carriers are captured by the traps, and the number of photoluminescent carriers decreases, thus reducing the emission intensity. Moreover, the luminescent centers of the phosphors are trivalent Ce³⁺ ions, therefore, RA-annealing is very beneficial for much more trivalent Ce³⁺ formation via Ce⁴⁺→Ce³⁺. As a result, the PL intensity of LYGAGGCV-2 is higher than that of LYGAGGCV-1. It must be emphasized that no emission of V³⁺ is observed in all phosphors, suggesting that the V ion dopant just acted as trap center [24]. Otherwise, after LYGAGGCV-0 phosphor was annealed in air atmosphere and in a weak reducing atmosphere, its fluorescence quantum yield (QY) is increased from 68.2% to 72.7% for LYGAGGCV-1 and 74.3% for LYGAGGCV-2, respectively. That is to say, the QY of LYGAGGCV-2 phosphor is the highest of these three phosphors, with more trivalent Ce³⁺ luminescent centers induced by reductive gas annealing. As for the analysis results of Ce and V ions valence states, please refer to the Supporting Information with Fig. S1, Table S1, and Fig. S2.

 

Fig. 2. (a) PL spectra excited at 450 nm and (b) normalized PLE spectra monitored at 500 nm, for LYGAGGCV-0, LYGAGGCV-1, and LYGAGGCV-2.

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3.2 TL property and defects source

3.2.1 Effect of the atmospheric treatment on TL property

TL measurement is one of the most effective ways to detect trap concentration and trap distribution [30]. TL curves were collected at a heating rate of 0.5 K/s after pre-excitation under 365 nm for 100 s and then delayed 5 min. Figure 3(a) describes TL curves of the three phosphors with different atmospheres treatment. The insert is the relative value of integrated TL spectra area ratio (temperature range from 300 K to 750 K) for the three phosphors. The intensity of T1 and T2 peaks of LYGAGGCV-1, annealed in air, decreases slightly, and the integrated area of TL is only 0.82 times that of LYGAGGCV-0. Interestingly, after annealing in a weak reducing atmosphere, the TL peaks (T1 and T2) of LYGAGGCV-2 are significantly enhanced and its integrated area of TL is 7.46 times that of LYGAGGCV-0, as indicated in the inset of Fig. 3(a). Additionally, the peaks of T1 and T2 move to a higher temperature region, indicating that annealing in a weak reducing atmosphere not only can induce plenty of deeper traps but can also stably store more carriers, which are very beneficial to improve the performance of optical information storage. The relative trap depth calculated by Urbach empirical formula [31] is presented in Table 1 as follows. The deepest trap depth of LYGAGGCV-2 is a high value of 1.264 eV, while the trap depth of LYGAGGCV-0 and LYGAGGCV-1 is only 1.186 eV and 1.196 eV, respectively. In addition, Fig. 3(b) presents the three-dimensional (3D) TL spectrum of LYGAGGCV-2, in which the thermal stimulated luminescence (TSL) spectrum peak position is consistent with PL peak position located at about 500 nm, meaning that the stored information can be also read-out by thermal stimulation. As for the origin of a large number of traps formed in the LYGAGGCV-2, it is speculated that the enhanced deep or shallow traps presented in TL spectra should be associated with defects related to oxygen vacancies and the annealing in different atmospheres can also effectively tailoring trap properties, because there have been some previous research results on defects of oxygen vacancy formation via reducing atmosphere heat-treatment [32,33].

 

Fig. 3. (a) TL spectra and relative TL integrated area ratios (inset) of LYGAGGCV-0, LYGAGGCV-1, and LYGAGGCV-2. (b) 3D TL spectrum of LYGAGGCV-2. All TL spectra are measured after 365 nm light covering for 100 s and delayed 5 min, with a heating rate of 0.5 K/s.

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Table 1. TL peaks with calculated trap depth of LYGAGGCV-0, LYGAGGCV-1, and LYGAGGCV-2 phosphors

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3.2.2 Effects of time and temperature on TL and trap properties

Time- and temperature-dependent TL spectra were used to further research the trap properties related to optical information storage performance of phosphors. Firstly, the time-dependent TL spectra recorded at various excitation duration (5-600 s) with the excitation source of instrument are applied to study the trap concentration and trap distribution of LYGAGGCV-2, as shown in Fig. 4(a). Figure 4(b) shows the intensity change of peak T1 and T2 with excitation duration increasing. When excitation duration is less than 100 s, the intensity of T1 and T2 increases rapidly as the excitation time is extended. And when the excitation duration exceeds 100 s, the increasing trend of T1 (shallow trap, marked in red color) integrated intensity is almost ceased, indicating that carriers captured by shallow traps gradually tends to be saturated. While the integrated intensity of T2 (deep trap, marked in blue color) still keeps on increasing, suggesting that the carriers captured by deep traps continuously increasing and the deep traps can stably capture more carriers than shallow traps. Therefore, it can be speculated that LYGAGGCV-2 phosphors can continuously absorb the energy from the incident light and capture much more carriers by deep traps, which is an indispensable property to store information stably and read-out information by photostimulation.

 

Fig. 4. (a) TL spectra and (b) the integrated intensity of T1 and T2, recorded at various excitation durations (5-600 s), for LYGAGGCV-2 sample.

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Secondly, the time-dependent TL spectra of LYGAGGCV-2 were also recorded at various delay durations (5 min-1440 h) after excitation with 365 nm UV light, and the relative TL integrated areas (in a temperature range from 300 K to 750 K) at various delay durations are plotted, as shown in Fig. 5. As the delay duration increases, the intensity of T1 drops rapidly while T2 intensity decreases slowly, and the position of two peaks moves towards higher temperature region (Fig. 5(a)). With the delay durations prolonged, the traps in LYGAGGCV-2 are inevitably interfered by thermal energy from the ambient temperature. As a result, it is easy for carriers to escape from shallow traps, while hard to escape from deep traps unless the shallow traps are emptied. This further confirms the existence of a continuous distribution of traps in LYGAGGCV-2, presenting a same phenomenon as seen in the work of Jin et al. [23]. In his work, with the increase of decay time, the TL intensity of Ba₂SiO₄:0.005Eu²⁺,0.01Ho³⁺ phosphors decreased significantly but the position of TL band obviously shifted to higher temperature region. Surprisingly, after delay duration prolonged to 1440 h (60 days), the total TL integrated area of LYGAGGCV-2 can still retain 47% of the value recorded after the phosphor delayed 5 min, as displayed in Fig. 5(b). This further indicates that the abundant trap levels in LYGAGGCV-2 offer an appropriate energy barrier to sustain a long-term storage of information.

 

Fig. 5. (a) TL spectra of LYGAGGCV-2 recorded at various delay durations (5 min-1440 h) after 365 nm light irradiating for 100 s. (b) Relative TL integral area ratio for various delay durations.

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Thirdly, Fig. 6 shows the recorded temperature-dependent TL spectra of LYGAGGCV-2 at various excitation temperatures (400-673 K) when irradiated by 365 nm UV light. It is worth noting that the intensity of T1 rapidly decays and its peak position shifts towards higher temperature as the excitation temperature increases and T1 nearly disappears when the excitation temperature increases to 475 K. That’s because the increase of excitation temperature causes the raising of thermal energy, leading to the gradual release of carriers captured by shallow traps owing to the intensive thermal disturbance. Meanwhile, the intensity of T2 increases first in a range of 400-525 K (Fig. 6(a)) and then decreases with the excitation temperature further increasing from 525 to 673 K (Fig. 6(b)), which is obviously different from that of T1. The reason for TL increases below 525 K is that the carriers generated by the light irradiation are gradually captured by deep traps, and at the same time the carriers released by the shallow traps owing to thermal disturbance are also captured by deep traps. When the excitation temperature exceeds 525 K, with the help of higher thermal energy, the carriers are no longer stably stay in the deep traps and are gradually released from trap levels, leading to less and less carriers stored in deep traps and a decreased tendency of T2 intensity. This abnormal change in the temperature-dependent TL spectra has been also reported in other material systems [34,35]. Moreover, with the excitation temperature increasing, the peak positions of T1 and T2 shift towards higher temperature region, suggesting that shallow traps are emptied first and then with deep traps empty followed. It, at the same time, shows a continuous distribution of traps in LYGAGGCV-2 [24].

 

Fig. 6. TL spectra recorded at various excitation temperatures (a) in the range of lower 400-525 K. (b) in the range of higher 525-673 K. All TL spectra are measured with a heating rate of 0.5 K/s.

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For a more comprehensive understanding of the “wave fluctuation” of TL intensity variation in the wide temperature range of 400-673 K shown in Fig. 6, the temperature-dependent photoluminescence (PL) spectra were recorded using λ_ex=450 nm, as indicated in Fig. 7(a), measured from 298 K to 573 K for LYGAGGCV-2 phosphor. With the tested temperature increasing, the luminescence intensity has experienced a process of first decreasing, then increasing and finally decreasing, also a “wave fluctuation” variation. The relationship between the tested temperature and the relative PL integrated intensity area (the wavelength ranges from 460 nm to 650 nm) is plotted in Fig. 7(b). The reason for the abnormal increase between 423 K and 498 K is related to the charge carriers stored in traps, that is to say, the carriers captured by traps are gradually released to continuously compensate for the luminescence intensity loss due to temperature quenching under the more intensive disturbance of thermal energy. What’s more, this abnormal temperature range of 423-498 K is fantastically consistent with the above temperature range for T2 intensity enhancement in temperature-dependent TL spectra (right part, Fig. 6(a)), indicating that the abnormal increase in PL intensity directly links to the properties of deep traps and the behaviors of carriers captured by deep traps. Further, the decrease of luminescence intensity above 498 K may be from the normal non-radiative transition occurring in the high temperature heating process, and because of the much higher thermal energy, the carriers stored stably in deep traps are less and difficult to continuously compensate for the loss of emission intensity. The particular phenomena have been discovered in other materials in the literatures, such as Sr₃SiO₅:Eu²⁺,Tm³⁺ exhibits an undetectable emission intensity loss with increasing temperature from 303 K to 393 K [36]. Moreover, at 573 K, for LYGAGGCV-2, its luminous intensity can still maintain 91.6% of that measured at room temperature, exhibiting a good fluorescence thermal stability, much higher than YGAG:Ce,V phosphor [24].

 

Fig. 7. (a) Temperature-dependent PL spectra of LYGAGGCV-2 recorded at various temperatures (298-573 K) under 450 nm excitation. The inset is enlarged partial high temperature-dependent PL spectra from 475 nm to 550 nm. (b) Normalized temperature dependence of integrated area of emission spectrum of LYGAGGCV-2.

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Obviously, on the basis of the above TL results, it is noted that LYGAGGCV-2 phosphors, after annealing in a weak reducing atmosphere, own abundant traps, which may be associated with defects related to oxygen vacancies. To further figure out the trap types, a combining of TL results with electron paramagnetic resonance (EPR) results is used to obtain a deep analyzation. Generally, according to the presented TL results, it can be reasonably speculated that the deep or shallow traps in LYGAGGCV-2 phosphors after annealing in an oxygen-deficient reductive atmosphere might be from oxygen vacancies. In addition, the existence of oxygen vacancies has been evidenced by EPR spectra measurements, as depicted in Fig. 8, where the black curve was recorded without 365 nm light irradiation and the red curve was recorded after 365 nm light irradiation for 5 min. The EPR spectra of LYGAGGCV-2 shows a sharp g-factor value of 2.0023, generally assigned to the oxygen vacancies with unpaired electrons [37,38]. What’s more, the EPR peak intensity after 365 nm light irradiation is stronger than that without 365 nm light irradiation, because the traps in phosphors could constantly capture electrons under excitation by 365 nm light. Therefore, various unpaired electrons are captured by plenty of oxygen vacancies, resulting in the EPR intensity increases.

 

Fig. 8. EPR spectra of LYGAGGCV-2. Black curve: without 365 nm light irradiation. Red curve: after 365 nm light irradiation for 5 min.

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3.3 Characterization and display of optical information storage

Based on above results, there are plenty of traps in LYGAGGCV-2, which are helpful to improve optical information storage properties. Therefore, strategies of optical stimulation and high-temperature thermal stimulation are adopted to vividly demonstrate the optical information storage properties of this phosphor. Normally, PSL is a release process of carriers stored in the traps by means of optical stimulation and is closely related to the properties of traps. Under the stimulation of 808 nm laser, the pre-irradiated LYGAGGCV-2 phosphor presents a strong PSL emission even after 5 min decay in the dark. As shown in Fig. 9(a), there is no significant difference of emission peak position and spectrum shape between PSL emission spectrum (λ_ex=808 nm) and PL emission spectrum (λ_ex=450 nm). The PSL spectrum shows an asymmetric emission peak at ∼500 nm, which is due to the 5d₁→4f transition of Ce³⁺, demonstrating the homology of the activator in the PL process (Fig. 9(b)).

 

Fig. 9. (a) PSL spectrum of LYGAGGCV-2, with 365 nm light irradiating for 100 s before measured, delayed 5 min, excited at 808 nm. (b) PL spectrum of LYGAGGCV-2, excited at 450 nm.

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As an alternative to photostimulation, external thermal stimulation can also trigger the retrieval of different information using photomasks methods. Hence, we prepared a flexible LYGAGGCV-2 phosphor film to vividly show a rapid photo-stimulated write-in and thermal-stimulated read-out approach for the whole storage media of film through a series of schematic pictures of optical information storage. The schematic diagram of information writing (405 nm laser irradiation) and reading (a 250 °C hot plate heating) is shown in Fig. 10(b-c), without mask. When covering mask on the film, at first, optical information can be encoded on the flexible film by a 405 nm laser irradiation, passing through three different hollowed patterns i-iii marked in Fig. 10 (d). The hollowed patterns are formed by photomasks and highlighted by the dotted lines. After irradiation, optical patterns can be decoded by heating the irradiated film on a 250 °C hot plate, with emitting a strong cyan light pattern, as shown in Fig. 10(e). The cyan emitting patterns on film shown in Fig. 10(e) is consistent with the hollowed mask patterns in Fig. 10(d). The demonstration result indicates that only the optical information is pre-written on the film by the 405 nm laser irradiation, the thermal stimulation can generate a bright cyan light read-out information, otherwise no visible information is detectable.

 

Fig. 10. (a) Photo of the flexible LYGAGGCV-2 phosphor film. Schematic illustration of information storage on the sheet of film: (b) written-in with 405 nm laser irradiation, with cyan light emitting; (c) read-out by heating on a 250 °C hot plate, with cyan light emitting; (d) different hollowed patterns created by photomasks, covered on the sheet of film (i, ii, and iii); (e) optical information read-out, passing through the different patterns, by putting the covered sheet of film on a 250 °C hot plate (i-1, ii-1 and iii-1), after 405 nm laser irradiating for 5 min.

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4. Conclusion

To induce the traps for realizing optical information storage, the designed and prepared multicomponent LuYGdAl₄GaO₁₂:Ce³⁺,V³⁺ (LYGAGGCV-0) phosphor was annealed in two different atmospheres, which could effectively modulate trap properties, especially annealing in a weak reducing atmosphere. Remarkably, after annealing in a weak reducing atmosphere, the TL intensity of LYGAGGCV-2 phosphor significantly increases, indicating that there are plenty of traps generated in the phosphor. Additionally, the time- and temperature-dependent TL results show the existence of m000ultiple trap levels with continuous distribution in the LYGAGGCV-2 rather than discrete trap levels. Further, LYGAGGCV-2 was found to be a promising phosphor for optical information storage, which has been confirmed that the peak position of PL upon 365 nm excitation is consistent with the peak position of PSL under NIR stimulation of 808 nm laser. And a demonstration confirmed the optical information write-in and read-out performance in the phosphor film, by a 405 nm laser as write-in light source and thermal stimulating as read-out source. Based on above results, the presented LYGAGGCV-2 is a good candidate material for optical information storage.