A high-luminous-efficiency germanate red-light perovskite quantum dot glass and its preparation method

Abstract

The present invention provides a high luminous efficiency germanate red light perovskite quantum dot glass and a preparation method thereof, belonging to the field of solid luminescent materials. The present invention involves doping Nb into the germanate red light perovskite quantum dot glass. 5+ , effectively increasing the fluorescence quantum yield of the glass, thereby improving its optical properties; annealing the glass melt removes internal stress generated during the cooling process, thereby improving the glass's stability; and finally, heat treatment further enhances the thermal stability of the germanium glass, resulting in a germanium-containing red-light perovskite quantum dot glass with excellent optical properties and good thermal stability. The results of the examples demonstrate that the germanium-containing red-light perovskite quantum dot glass prepared by the preparation method provided by the present invention not only exhibits excellent optical properties but also exhibits good thermal stability.

Description

Technical Field

[0001] The present invention relates to the field of solid luminescent materials, and in particular to a high-luminescent-efficiency germanate red-light perovskite quantum dot glass and a preparation method thereof. Background Art

[0002] In recent years, all-inorganic perovskite quantum dots (PQDs) have been widely used in optoelectronic devices such as solar cells, light-emitting diodes (LEDs), and lasers due to their tunable emission peaks, narrow emission spectra, high fluorescence quantum efficiency, easy preparation, and strong defect tolerance. However, stability issues hinder their application due to their inherent crystal structure, ion exchange of surface ligands, and unusual sensitivity to environmental factors such as light, water, oxygen, and heat. Oxide glass materials, on the other hand, offer advantages such as a dense network structure, high stability, and ease of preparation. Encapsulating PQDs in inorganic glass materials has become an effective means of improving their stability. Although CsPbBrI2 PQDs have been applied in various fields, their optoelectronic performance and stability still struggle to meet technical requirements. With technological advancements, various fields have placed higher demands on the optoelectronic performance and stability of PQDs, and traditional PQD glasses are no longer able to meet these requirements.

[0003] Therefore, how to improve the photoelectric performance and stability of CsPbBrI2 perovskite quantum dots has become a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0004] The object of the present invention is to provide a high-luminous-efficiency germanium-based red-light perovskite quantum dot glass and a preparation method thereof. The germanium-based red-light perovskite quantum dot glass prepared by the preparation method provided by the present invention not only has excellent optical properties but also has good thermal stability.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a germanium-based red-light perovskite quantum dot glass with high luminous efficiency, comprising the following steps:

[0007] (1) H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 are mixed and melted to obtain a glass melt;

[0008] (2) annealing the glass melt obtained in step (1) to obtain a glass block;

[0009] (3) heat-treating the glass block obtained in step (2) to obtain high-luminescence-efficiency germanium-containing red-light perovskite quantum dot glass.

[0010] Preferably, in step (1), the molar ratio of H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 is (35-55): (25-40): (4-6): (3-5): (4-6): (2.5-3): 2: 4: (0.7-3.5).

[0011] Preferably, the molar ratio of H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 is 40:40:4:3:4.5:2.5:2:4:(0.7~3.5).

[0012] Preferably, the melting and holding temperature in step (1) is 900-1050° C., and the melting and holding time is 10-40 minutes.

[0013] Preferably, the melting holding temperature is 1000° C., and the melting holding time is 20 minutes.

[0014] Preferably, the holding temperature of the annealing treatment in step (2) is 300-400° C., and the holding time of the annealing treatment is 2-5 hours.

[0015] Preferably, the holding temperature of the annealing treatment is 350° C., and the holding time of the annealing treatment is 3 hours.

[0016] Preferably, the holding temperature of the heat treatment in step (3) is 500-550° C., and the holding time of the heat treatment is 3-6 hours.

[0017] Preferably, the holding temperature of the heat treatment is 520° C., and the holding time of the heat treatment is 4 hours.

[0018] The present invention provides a germanate red light perovskite quantum dot glass with high luminous efficiency prepared by the preparation method described in the above technical solution.

[0019] The present invention provides a method for preparing a germanium-based red light perovskite quantum dot glass with high luminous efficiency, comprising the following steps: (1) mixing H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 and melting the mixture to obtain a glass melt; (2) annealing the glass melt obtained in step (1) to obtain a glass block; (3) heat-treating the glass block obtained in step (2) to obtain a germanium-based red light perovskite quantum dot glass with high luminous efficiency. The present invention involves doping Nb into the germanium-based red light perovskite quantum dot glass. 5+, effectively increasing the fluorescence quantum yield of the glass, thereby improving its optical properties; annealing the glass melt removes internal stress generated during the cooling process, thereby improving the glass's stability; and finally, heat treatment further enhances the thermal stability of the germanium glass, resulting in a germanium-containing red-light perovskite quantum dot glass with excellent optical properties and good thermal stability. The results of the examples demonstrate that the germanium-containing red-light perovskite quantum dot glass provided by the present invention not only exhibits excellent optical properties but also has good thermal stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 XRD patterns of the germanate red-light perovskite quantum dot glasses obtained in Examples 1 to 5 and Comparative Example 1;

[0021] Figure 2 TEM image of the germanate red light perovskite quantum dot glass obtained in Example 3;

[0022] Figure 3 This is a size distribution histogram of the germanate red light perovskite quantum dot glass obtained in Example 3;

[0023] Figure 4 This is the HTEM image of the germanate red light perovskite quantum dot glass obtained in Example 3;

[0024] Figure 5 The emission spectra of the germanate red light perovskite quantum dot glass obtained in Examples 1 to 5 and Comparative Example 1;

[0025] Figure 6 FTIR image of the germanate red light perovskite quantum dot glass obtained in Example 3;

[0026] Figure 7 This is the Raman spectrum of the germanate red light perovskite quantum dot glass obtained in Example 3;

[0027] Figure 8 This is the heating spectrum of the germanate red light perovskite quantum dot glass obtained in Example 3;

[0028] Figure 9 This is the cooling spectrum of the germanate red light perovskite quantum dot glass obtained in Example 3;

[0029] Figure 10 This is the luminescence intensity change curve of the germanate red light perovskite quantum dot glass obtained in Example 3 during the heating and cooling processes. DETAILED DESCRIPTION

[0030] The present invention provides a method for preparing a germanium-based red-light perovskite quantum dot glass with high luminous efficiency, comprising the following steps:

[0031] (1) H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 are mixed and melted to obtain a glass melt;

[0032] (2) annealing the glass melt obtained in step (1) to obtain a glass block;

[0033] (3) heat-treating the glass block obtained in step (2) to obtain high-luminescence-efficiency germanium-containing red-light perovskite quantum dot glass.

[0034] The present invention mixes H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 and then melts the mixture to obtain a glass melt.

[0035] In the present invention, unless otherwise specified, the raw materials used are commercially available products well known to those skilled in the art or products prepared using processes well known to those skilled in the art.

[0036] In the present invention, the molar ratio of H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr, and Nb2O5 is preferably (35-55):(25-40):(4-6):(3-5):(4-6):(2.5-3):2:4:(0.7-3.5), and more preferably 40:40:4:3:4.5:2.5:2:4:(0.7-3.5). By controlling the amount of the raw materials, the present invention can further improve the optical properties and chemical stability of the glass.

[0037] The present invention has no particular limitation on the specific operation of mixing, which can be determined based on the technical common sense of those skilled in the art.

[0038] In the present invention, the melting is preferably carried out in a muffle furnace. The present invention has no particular limitation on the specific model of the muffle furnace, and a commercially available muffle furnace well known to those skilled in the art can be used.

[0039] In the present invention, the melting holding temperature is preferably 900-1050°C, more preferably 1000°C; the melting holding time is preferably 10-40 minutes, more preferably 20 minutes. By controlling the melting process parameters, the present invention can ensure that the raw materials are completely melted to form a uniform glass melt.

[0040] After obtaining the glass melt, the present invention performs annealing treatment on the glass melt to obtain a glass block.

[0041] In the present invention, the annealing treatment is preferably performed by pouring the molten glass onto a preheating plate and then transferring it to an annealing furnace for annealing. This method can prevent the rapid cooling of the molten glass in air from causing excessive internal stress and cracking of the glass block.

[0042] In the present invention, the holding temperature of the annealing treatment is preferably 300-400° C., more preferably 350° C.; the holding time of the annealing treatment is preferably 2-5 hours, more preferably 3 hours. The present invention can eliminate internal stress in the glass block through annealing treatment.

[0043] After obtaining the glass block, the present invention performs heat treatment on the glass block to obtain high-luminous-efficiency germanate red-light perovskite quantum dot glass.

[0044] In the present invention, the holding temperature of the heat treatment is preferably 500-550°C, more preferably 520°C; the holding time of the heat treatment is preferably 3-6 hours, more preferably 4 hours. The present invention can further improve the thermal stability of the germanate red light perovskite quantum dot glass through heat treatment.

[0045] The present invention adds Nb into the germanate red light perovskite quantum dot glass. 5+ , which can effectively improve the fluorescence quantum yield of the glass, thereby improving its optical properties; by annealing the glass melt, the internal stress generated in the glass during the cooling process can be removed, thereby improving the stability of the glass; finally, the thermal stability of the germanium glass can be further improved by heat treatment, thereby obtaining germanium salt red light perovskite quantum dot glass with excellent optical properties and good thermal stability.

[0046] The present invention provides a germanate red light perovskite quantum dot glass with high luminous efficiency prepared by the preparation method described in the above technical solution.

[0047] The germanate red light perovskite quantum dot glass provided by the present invention has high fluorescence quantum yield, excellent luminescence properties, and good thermal stability.

[0048] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0049] Example 1

[0050] A method for preparing high-luminous-efficiency germanate red-light perovskite quantum dot glass comprises the following steps:

[0051] (1) H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 are mixed and melted in a muffle furnace to obtain a glass melt; the molar ratio of H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 is 40:40:4:3:4.5:2.5:2:4:0.7; the melting holding temperature is 1000°C and the melting holding time is 20 minutes;

[0052] (2) pouring the glass melt obtained in step (1) onto a preheating plate, and then transferring it to an annealing furnace for annealing to obtain a glass block; the annealing treatment is carried out at a holding temperature of 350° C. and a holding time of 3 hours;

[0053] (3) The glass block obtained in step (2) is heat-treated to obtain a high-luminous-efficiency germanium salt red-light perovskite quantum dot glass, which is denoted as PG1; the heat treatment temperature is 520° C., and the heat treatment time is 4 hours.

[0054] Example 2

[0055] A method for preparing high-luminous-efficiency germanate red-light perovskite quantum dot glass comprises the following steps:

[0056] (1) H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 are mixed and melted in a muffle furnace to obtain a glass melt; the molar ratio of H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 is 40:40:4:3:4.5:2.5:2:4:1.4; the melting holding temperature is 1000°C and the melting holding time is 20 minutes;

[0057] (2) pouring the glass melt obtained in step (1) onto a preheating plate, and then transferring it to an annealing furnace for annealing to obtain a glass block; the annealing treatment is carried out at a holding temperature of 350° C. and a holding time of 3 hours;

[0058] (3) The glass block obtained in step (2) is heat-treated to obtain a high-luminous-efficiency germanium salt red-light perovskite quantum dot glass, which is denoted as PG2; the heat treatment is carried out at a holding temperature of 520° C. for 4 hours.

[0059] Example 3

[0060] A method for preparing high-luminous-efficiency germanate red-light perovskite quantum dot glass comprises the following steps:

[0061] (1) H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 are mixed and melted in a muffle furnace to obtain a glass melt; the molar ratio of H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 is 40:40:4:3:4.5:2.5:2:4:2.1; the melting holding temperature is 1000°C, and the melting holding time is 20 minutes;

[0062] (2) pouring the glass melt obtained in step (1) onto a preheating plate, and then transferring it to an annealing furnace for annealing to obtain a glass block; the annealing treatment is carried out at a holding temperature of 350° C. and a holding time of 3 hours;

[0063] (3) The glass block obtained in step (2) is heat-treated to obtain a high-luminous-efficiency germanium salt red-light perovskite quantum dot glass, which is denoted as PG3; the heat treatment is carried out at a holding temperature of 520° C. and a heat treatment time of 4 h.

[0064] Example 4

[0065] A method for preparing high-luminous-efficiency germanate red-light perovskite quantum dot glass comprises the following steps:

[0066] (1) H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 are mixed and melted in a muffle furnace to obtain a glass melt; the molar ratio of H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 is 40:40:4:3:4.5:2.5:2:4:2.8; the melting holding temperature is 1000°C, and the melting holding time is 20 minutes;

[0067] (2) pouring the glass melt obtained in step (1) onto a preheating plate, and then transferring it to an annealing furnace for annealing to obtain a glass block; the annealing treatment is carried out at a holding temperature of 350° C. and a holding time of 3 hours;

[0068] (3) The glass block obtained in step (2) is heat-treated to obtain a high-luminous-efficiency germanium salt red-light perovskite quantum dot glass, which is denoted as PG4; the heat treatment is carried out at a holding temperature of 520° C. for 4 hours.

[0069] Example 5

[0070] A method for preparing high-luminous-efficiency germanate red-light perovskite quantum dot glass comprises the following steps:

[0071] (1) H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 are mixed and melted in a muffle furnace to obtain a glass melt; the molar ratio of H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 is 40:40:4:3:4.5:2.5:2:4:3.5; the melting holding temperature is 1000°C and the melting holding time is 20 minutes;

[0072] (2) pouring the glass melt obtained in step (1) onto a preheating plate, and then transferring it to an annealing furnace for annealing to obtain a glass block; the annealing treatment is carried out at a holding temperature of 350° C. and a holding time of 3 hours;

[0073] (3) The glass block obtained in step (2) is heat-treated to obtain a high-luminous-efficiency germanium salt red-light perovskite quantum dot glass, which is denoted as PG5; the heat treatment temperature is 520° C., and the heat treatment time is 4 hours.

[0074] Comparative Example 1

[0075] A method for preparing germanate red light perovskite quantum dot glass comprises the following steps:

[0076] (1) H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI and NbBr are mixed and melted in a muffle furnace to obtain a glass melt; the molar ratio of H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI and NbBr is 40:40:4:3:4.5:2.5:2:4; the melting holding temperature is 1000°C, and the melting holding time is 20 minutes;

[0077] (2) pouring the glass melt obtained in step (1) onto a preheating plate, and then transferring it to an annealing furnace for annealing to obtain a glass block; the annealing treatment is carried out at a holding temperature of 350° C. and a holding time of 3 hours;

[0078] (3) The glass block obtained in step (2) is heat-treated to obtain germanium salt red light perovskite quantum dot glass, which is recorded as PG0; the holding temperature of the heat treatment is 520° C., and the holding time of the heat treatment is 4 hours.

[0079] The red-light germanate perovskite quantum dot glasses obtained in Examples 1 to 5 and Comparative Example 1 were characterized by X-ray diffraction (XRD) (D2 phase shifter, Bruker, Karlsruhe). Figure 1As shown. Figure 1 It can be seen that the XRD diffraction peak corresponding to the CsPbBrI2 perovskite quantum dots is observed in the XRD diffraction pattern, proving that the CsPbBrI2 perovskite quantum dots are precipitated in the glass.

[0080] The germanate red light perovskite quantum dot glass obtained in Example 3 was observed using a JEOL JEM-F200 transmission electron microscope (TEM). The TEM image obtained is as follows: Figure 2 The size distribution histogram obtained is shown in Figure 3 The obtained HTEM images are shown in Figure 4 As shown. Figures 2-4 It can be seen that many black spherical particles are precipitated in the glass. The average particle size of the particles is about 5.89 nm, and the interplanar spacing is 0.216 nm, corresponding to the (220) crystal plane of CsPbBrI2 perovskite quantum dots, further proving that CsPbBrI2 perovskite quantum dots have been successfully precipitated in germanate glass.

[0081] The red-light germanate perovskite quantum dot glasses obtained in Examples 1 to 5 and Comparative Example 1 were observed using a fluorescence spectrometer with a 450W xenon lamp. The emission spectra obtained are as follows: Figure 5 As shown. Figure 5 It can be seen that the emission spectrum peak of the germanate red light perovskite quantum dot glass is located at 660-680 nanometers.

[0082] The germanate red light perovskite quantum dot glass obtained in Example 3 was observed using an FTIR infrared spectrometer. The obtained FTIR graph is as follows: Figure 6 The Raman spectrum obtained is shown in Figure 7 As shown. Figure 6 and Figure 7 It can be seen that as Nb 5+ With the addition of ions, the bridging oxygen bonds of the [BO4] tetrahedron are destroyed, and the number of [BO3] triangles increases, causing the glass network structure to become loose, providing space for the growth and nucleation of perovskite quantum dots.

[0083] Figure 8 This is the heating spectrum of the germanate red light perovskite quantum dot glass obtained in Example 3. Figure 9 This is the cooling spectrum of the germanate red light perovskite quantum dot glass obtained in Example 3. Figure 10 The luminescence intensity variation curve of the germanate red light perovskite quantum dot glass obtained in Example 3 during the heating and cooling process. Figures 8-10It can be seen that when the temperature gradually rises from room temperature, the luminescence intensity of the CsPbBrI2 perovskite quantum dot glass gradually decreases, and when the temperature gradually drops to room temperature, the luminescence of the perovskite quantum dot glass gradually recovers. At the same temperature, the intensity is even higher than when the temperature is increased, indicating that the CsPbBrI2 perovskite quantum dot glass has excellent temperature resilience.

[0084] From the above analysis, it can be seen that at the optimal in situ crystallization temperature, red light CsPbBrI2 perovskite quantum dot glass with high luminescence efficiency was prepared in germanate glass, and the prepared CsPbBrI2 perovskite quantum dot glass has excellent temperature resilience.

[0085] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing high-luminescence-efficiency germanate red-light perovskite quantum dot glass, comprising the following steps: (1) H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 are mixed and melted to obtain a glass melt; (2) annealing the glass melt obtained in step (1) to obtain a glass block; (3) heat-treating the glass block obtained in step (2) to obtain high-luminescence-efficiency germanium-containing red-light perovskite quantum dot glass.

2. The preparation method according to claim 1, characterized in that In the step (1), the molar ratio of H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 is (35-55): (25-40): (4-6): (3-5): (4-6): (2.5-3): 2: 4: (0.7-3.5).

3. The preparation method according to claim 2, characterized in that The molar ratio of H3BO3, GeO2, ZnO, CaO, Cs2CO3, PbO, NaI, NbBr and Nb2O5 is 40:40:4:3:4.5:2.5:2:4:(0.7~3.5).

4. The preparation method according to claim 1, characterized in that The holding temperature for melting in the step (1) is 900-1050° C., and the holding time for melting is 10-40 minutes.

5. The preparation method according to claim 4, characterized in that The melting holding temperature is 1000° C., and the melting holding time is 20 minutes.

6. The preparation method according to claim 1, characterized in that The holding temperature of the annealing treatment in step (2) is 300-400° C., and the holding time of the annealing treatment is 2-5 hours.

7. The preparation method according to claim 6, characterized in that The holding temperature of the annealing treatment is 350° C., and the holding time of the annealing treatment is 3 hours.

8. The preparation method according to claim 1, characterized in that The heat treatment in step (3) is carried out at a holding temperature of 500 to 550° C. and for a holding time of 3 to 6 hours.

9. The preparation method according to claim 8, characterized in that The holding temperature of the heat treatment is 520° C., and the holding time of the heat treatment is 4 hours.

10. The high luminous efficiency germanate red light perovskite quantum dot glass prepared by the preparation method according to any one of claims 1 to 9.

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