An integrated photocapacitor and its fabrication method

Abstract

This invention discloses an integrated photoelectric capacitor and its fabrication method, relating to the field of battery technology. The photoelectric capacitor includes a perovskite / heterojunction tandem solar cell energy conversion unit, a symmetrical supercapacitor energy storage unit, and a Janus symmetrical electrode. The fabrication method includes: S1 fabricating the perovskite / heterojunction tandem solar cell energy conversion unit, the symmetrical supercapacitor energy storage unit, and the Janus symmetrical electrode; S2 stacking the electrodes of the perovskite / heterojunction tandem solar cell energy conversion unit and the symmetrical supercapacitor energy storage unit on both sides of the Janus symmetrical electrode to fabricate the photoelectric capacitor; and a three-terminal photoelectric capacitor integrated with the perovskite / heterojunction tandem solar cell energy conversion unit and the symmetrical supercapacitor energy storage unit. By coordinating the energy matching between the perovskite / heterojunction tandem solar cell energy conversion unit and the symmetrical supercapacitor energy storage unit, and seeking the coincidence of the maximum power point and the synchronization of the maximum efficiency point, the solar energy conversion and storage efficiency exceeds 20%.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to an integrated photocapacitor and its fabrication method. Background Technology

[0002] Solar energy is clean and inexhaustible, but solar radiation on Earth is fluctuating, intermittent, and unstable. Therefore, the sustainable use of solar energy requires a complementary combination of efficient energy conversion and low-loss energy storage technologies. Batteries or supercapacitors can convert electrical energy into chemical energy and store it in devices. However, such energy storage devices are energy-limited, closed systems that require constant recharging. The complementary combination of efficient energy conversion and low-loss energy storage technologies achieves integrated solar energy conversion and storage, promoting the sustainable use of renewable energy and aligning with the current trend towards multifunctional and miniaturized electronic devices. Therefore, photoelectric capacitors, which integrate photoelectric conversion and electrochemical storage functions in a single device, represent an optimal choice that is cost-effective, volumetrically efficient, and functionally efficient.

[0003] The complex structure of multifunctional integrated energy conversion and storage units in a single device, especially the mismatch between the energy conversion and storage units, leads to low efficiency in the solar energy conversion process and large energy losses in the energy storage stage. Summary of the Invention

[0004] The purpose of this invention is to design an integrated photoelectric capacitor and its fabrication method to solve the above-mentioned problems.

[0005] The present invention achieves the above objectives through the following technical solutions:

[0006] An integrated photocapacitor, comprising:

[0007] The perovskite / heterojunction tandem solar cell energy conversion unit includes a doped heterojunction cell, a composite junction, and a perovskite cell, with the composite junction located between the doped heterojunction cell and the perovskite cell.

[0008] Symmetrical supercapacitor energy storage unit;

[0009] Janus symmetric electrode; the Janus symmetric electrode is connected to the doped heterojunction cell and the symmetric supercapacitor energy storage unit respectively. The upper end of the perovskite cell, the lower end of the symmetric supercapacitor energy storage unit, and the Janus symmetric electrode serve as conductive ports.

[0010] A method for fabricating an integrated photocapacitor, comprising:

[0011] S1. Prepare perovskite / heterojunction tandem solar cell energy conversion unit, symmetrical supercapacitor energy storage unit and Janus symmetrical electrode respectively;

[0012] S2. Stack the electrodes of the perovskite / heterojunction tandem solar cell energy conversion unit and the electrodes of the symmetrical supercapacitor energy storage unit on both sides of the Janus symmetrical electrode, place them in a mold, lead out the conductive ports, fill with epoxy resin, and dry to obtain an integrated photoelectric capacitor.

[0013] The specific steps involved in fabricating the energy conversion unit for a perovskite / heterojunction tandem solar cell include:

[0014] a. Surface texturing and damage removal of n-type single-crystal silicon substrates;

[0015] b. Depositing intrinsic amorphous silicon thin films on both sides of an n-type monocrystalline silicon layer;

[0016] c. Deposit a LiF thin film on the intrinsic amorphous silicon thin film on the first side;

[0017] d. Metallic Mg was deposited on LiF thin films by thermal evaporation, followed by post-annealing at 120°C to form an electron-selective mixed film layer;

[0018] e. Deposit Ag on the electron-selective mixed film to obtain a metal electrode;

[0019] f. Depositing MoO on the intrinsic amorphous silicon thin film on the second side x As a hole-selective transport layer;

[0020] g. Deposit a first IZO transparent conductive film as a composite junction on the hole selective transport layer;

[0021] h. Spin-coat the prepared SnO2 colloidal solution onto the composite junction at a speed of 3500 rpm;

[0022] i. Spin-coating a TiO2 colloidal solution onto a SnO2 layer at a speed of 4000 rpm to form an electron transport layer;

[0023] j. A perovskite thin film is deposited on the electron transport layer by an anti-solvent spin coating process to form a perovskite light-absorbing layer;

[0024] k. Spin-coating a spiro-OMeTAD layer as a hole transport layer;

[0025] l. A second IZO transparent conductive film is deposited on the hole transport layer by magnetron sputtering;

[0026] m. Silver grid lines are fabricated on the second IZO transparent conductive film as conductive ports to obtain a perovskite / doped heterojunction tandem solar cell energy conversion unit;

[0027] The specific steps involved in fabricating a symmetrical supercapacitor energy storage unit include:

[0028] ①. Oxidize flake graphite with an oxidizing agent, transfer the oxidized precipitate to a vacuum freeze dryer and freeze for 6-8 hours to obtain soft graphene oxide;

[0029] ②. The obtained graphene oxide was prepared into graphene powder by thermal exfoliation, and then the thermally exfoliated graphene powder was activated by chemical method (KOH).

[0030] ③. The activated graphene powder is uniformly mixed with a 5% (w / w) polytetrafluoroethylene aqueous solution to obtain a graphene paste;

[0031] ④. Press the graphene paste into a thin film using a 0.5 MPa roller press, and then dry it in a vacuum oven at 70°C to obtain a graphene electrode;

[0032] ⑤. Press two identical graphene electrodes into a 200-mesh copper mesh, leaving a 1mm gap between them, and fix them with epoxy resin;

[0033] ⑥. Fill the gap between the two graphene electrodes with Na2SO4 electrolyte;

[0034] ⑦. Seal the prepared device to obtain a symmetrical supercapacitor energy storage unit;

[0035] The fabrication of Janus symmetric electrodes specifically includes:

[0036] 1) Clean the copper foil in an ultrasonic generator for 15 minutes;

[0037] 2) Apply a thin layer of conductive silver paste to both sides of the copper foil;

[0038] 3) Place the copper foil coated with conductive silver paste into an oven and dry it to obtain the Janus symmetric electrode.

[0039] The beneficial effects of this invention are as follows: An integrated photoelectric capacitor is a three-terminal photoelectric capacitor integrated with a perovskite / heterojunction tandem solar cell energy conversion unit and a symmetrical supercapacitor energy storage unit. By coordinating the energy matching between the perovskite / heterojunction tandem solar cell energy conversion unit and the symmetrical supercapacitor energy storage unit, and seeking the coincidence of the maximum power point and the synchronization of the maximum efficiency point, the solar energy conversion and storage efficiency of the integrated photoelectric capacitor exceeds 20%. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of an integrated photocapacitor in an embodiment of the present invention;

[0041] Figure 2 This is an equivalent circuit diagram of an embodiment of the present invention.

[0042] The corresponding figure labels are:

[0043] 001-T1 electrical terminal, 002-T2 electrical terminal, 003-T3 electrical terminal, 100-Perovskite / heterojunction tandem solar cell energy conversion unit, 200-Symmetric supercapacitor energy storage unit, 101-Silver grid line, 102-Spiro-OMeTAD hole transport layer, 103-Perovskite light-absorbing layer, 104-SnO2 / TiO2 electron transport layer, 105-Composite junction (IZO), 106-MoO x Hole-selective transport layer, 107-intrinsic hydrogenated amorphous silicon layer, 108-n-type monocrystalline silicon layer, 109-intrinsic hydrogenated amorphous silicon layer, 110-electron-selective mixed film layer, 111-metal electrode Ag, 201-collector electrode, 202-graphene electrode, 203-Na2SO4 electrolyte, 204-graphene electrode. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0046] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0047] In the description of this invention, it should be understood that the terms "upper," "lower," "inner," "outer," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0048] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0049] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, terms such as "set" and "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0050] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0051] An integrated photocapacitor, comprising:

[0052] The perovskite / heterojunction tandem solar cell energy conversion unit includes a doped heterojunction cell, a composite junction, and a perovskite cell, with the composite junction located between the doped heterojunction cell and the perovskite cell.

[0053] Symmetrical supercapacitor energy storage unit;

[0054] Janus symmetric electrode; the Janus symmetric electrode is connected to the doped heterojunction cell and the symmetric supercapacitor energy storage unit respectively. The upper end of the perovskite cell, the lower end of the symmetric supercapacitor energy storage unit, and the Janus symmetric electrode serve as conductive ports.

[0055] The perovskite solar cell consists of a hole transport layer, a perovskite light-absorbing layer, and an electron transport layer from top to bottom. The doped heterojunction solar cell consists of a hole-selective transport layer, an intrinsic hydrogenated amorphous silicon layer, an n-type monocrystalline silicon layer, an intrinsic hydrogenated amorphous silicon layer, an electron-selective mixed film layer, and a metal electrode from top to bottom. The composite junction is located between the electron transport layer and the hole-selective transport layer.

[0056] The structure of the symmetrical supercapacitor energy storage unit consists of a graphene electrode, a Na2SO4 electrolyte, and a graphene electrode, with a distance of 1 mm between the two graphene electrodes.

[0057] The Janus symmetric electrode is a copper foil coated with silver paste on both sides.

[0058] A method for fabricating an integrated photocapacitor, comprising:

[0059] (1) Surface texturing and damage removal are performed on n-type single-crystal silicon substrates;

[0060] (2) An intrinsic amorphous silicon thin film is deposited on both sides of an N-type single crystal silicon substrate using the PECVD method to form an intrinsic hydrogenated amorphous silicon layer.

[0061] (3) A LiF thin film was deposited on the intrinsic hydrogenated amorphous silicon layer on either side using a thermal evaporation method at a deposition rate of [value missing]. The thickness is 0.8 nm;

[0062] (4) Metallic Mg was deposited on LiF thin films using a thermal evaporation method at a deposition rate of [missing value]. With a thickness of 70 nm, an electron-selective hybrid film layer is formed by post-annealing at 120 °C.

[0063] (5) Ag is deposited on the electron-selective mixed film to obtain the metal electrode Ag;

[0064] (6) On the other side of the intrinsic hydrogenated amorphous silicon layer, MoO is deposited using a thermal evaporation method. x As a hole-selective transport layer, the deposition rate is Thickness is 70nm;

[0065] (7) In the hole-selective transport layer MoO x The first IZO transparent conductive film is deposited by radio frequency magnetron sputtering as a composite junction;

[0066] (8) Spin coat the SnO2 colloidal solution (diluted with ultrapure water to 3wt%) onto the composite junction at 3500 rpm for 20s, and then anneal at 120℃ for 30min;

[0067] (9) Under stirring at room temperature, 7 ml of oleic acid was slowly added to 20 ml of cyclohexane, followed by 5 ml of octadecylamine and 1 ml of tetrabutyl titanate. The mixture was then added to a 50 ml autoclave and reacted at 180 °C for 24 hours. After cooling to room temperature, the product was mixed with 200 ml of anhydrous ethanol and centrifuged. The precipitate was collected, and the obtained product was redispersed in 24 ml of toluene to obtain a stable TiO2 colloidal solution.

[0068] (10) Spin-coat the TiO2 colloidal solution obtained in step (9) onto the SnO2 layer at a speed of 4000 rpm for 20 s, and then anneal at 180 °C for 3 min. Repeat the deposition of TiO2 several times to meet the thickness requirement of 60-80 nm, and then anneal at 120 °C for 3 min to form an electron transport layer;

[0069] (11) A solution of 1.47M PbI2, 0.11M PbBr2, 1.4M FAI, 0.11M MABr and 0.5M MACl was added to a mixed solvent system of DMSO / DMF (volume ratio of 1 / 6) and stirred at 70°C for 1 hour to obtain a PVK precursor solution.

[0070] (12) The prepared PVK precursor solution was spin-coated onto the TiO2 layer. First, it was spin-coated at 1000 rpm for 10 s, then at 6000 rpm for 20 s. 5 s before the end of the spin-coating, 140 μL of chlorobenzene solution was dropped onto the spin substrate. The obtained film was annealed at 100 °C for 45 min to finally obtain a perovskite light-absorbing layer with a film thickness of 600 nm.

[0071] (13) spiro-OMeTAD (72.3 mg·mL) –1 The solution was spin-coated onto the perovskite light-absorbing layer at a speed of 4000 rpm and heated and dried for 10 min to finally obtain a hole transport layer with a thickness of 240 nm.

[0072] (14) Under vacuum, a second IZO transparent conductive film is deposited on the perovskite light-absorbing layer by magnetron sputtering, and then thermally evaporated to... A 100 nm silver grid electrode was deposited at a high rate to obtain a perovskite / doped heterojunction tandem solar cell energy conversion unit.

[0073] (15) Add strong acid to flake graphite, then add strong oxidizing KMnO4 powder, stir for 15 min, after the reaction is complete, cool to 0℃, add hydrogen peroxide (30%), then centrifuge for 10 min, wash with deionized water, transfer the paste precipitate to a vacuum freeze dryer and freeze for 6-8 hours to obtain soft graphene oxide.

[0074] (16) Place graphene oxide in a quartz boat and anneal it in a tube furnace at 1000°C for 60 min under argon protection to obtain graphene powder.

[0075] (17) Weigh 500mg of graphene powder and place it in a beaker. Add 2mg of KOH powder, add an appropriate amount of deionized water and ethanol, disperse in ultrasound for 3 hours, dry in a ventilation drying oven for 12 hours, and then place in a tube furnace. Under argon protection, maintain at 800℃ for 60 minutes to obtain activated thermally exfoliated graphene powder.

[0076] (18) The activated graphene powder was uniformly mixed with a 5% polytetrafluoroethylene aqueous solution, and ultrasonically treated for 15 minutes. The mixture was then stirred to obtain a graphene paste.

[0077] (19) The graphene paste was pressed into a thin film using a 0.5 MPa roller press, and then dried overnight in a vacuum oven at 70°C to obtain a graphene electrode.

[0078] (20) Press two identical graphene electrodes into a 200-mesh copper mesh to serve as symmetrical electrodes for a symmetrical supercapacitor energy storage unit. Use epoxy resin to fix the two graphene electrodes face to face and separate them with a 1mm gap.

[0079] (21) After solidification, a 1 mol / L Na2SO4 aqueous solution was used as an electrolyte to fill the 1 mm gap, and then the device was sealed to obtain a symmetrical supercapacitor energy storage unit.

[0080] (22) Clean the copper foil in an ultrasonic generator for 15 minutes, coat a thin layer of conductive silver paste on both sides of the copper foil, and dry it in an oven to obtain Janus symmetric electrodes.

[0081] (23) The collector of the prepared symmetrical supercapacitor energy storage unit is connected to the metal electrode Ag of the perovskite / doped heterojunction tandem solar cell energy conversion unit through Janus symmetrical electrode, placed in a self-made mold, and conductive ports are led out respectively. Epoxy resin is filled and cured at 75°C for 30 minutes to complete the preparation of the integrated photoelectric capacitor and obtain an integrated photoelectric capacitor with a conversion storage efficiency of 20.53%.

[0082] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. An integrated photocapacitor, characterized in that, include: The perovskite / heterojunction tandem solar cell energy conversion unit includes a doped heterojunction cell, a composite junction, and a perovskite cell, with the composite junction located between the doped heterojunction cell and the perovskite cell. Symmetrical supercapacitor energy storage unit; The structure of the symmetric supercapacitor energy storage unit consists of a graphene electrode, a Na2SO4 electrolyte, and a graphene electrode, with a distance of 1 mm between the two graphene electrodes. Janus symmetric electrode; the Janus symmetric electrode is connected to the doped heterojunction cell and the symmetric supercapacitor energy storage unit respectively. The upper end of the perovskite cell, the lower end of the symmetric supercapacitor energy storage unit and the Janus symmetric electrode serve as conductive ports; the Janus symmetric electrode is a copper foil coated with silver paste on both sides. The perovskite solar cell consists of a hole transport layer, a perovskite light-absorbing layer, and an electron transport layer from top to bottom. The doped heterojunction solar cell consists of a hole-selective transport layer, an intrinsic hydrogenated amorphous silicon layer, an n-type monocrystalline silicon layer, an intrinsic hydrogenated amorphous silicon layer, an electron-selective mixed film layer, and a metal electrode from top to bottom. The composite junction is located between the electron transport layer and the hole-selective transport layer.

2. A method for fabricating an integrated photocapacitor, used to fabricate the integrated photocapacitor as described in claim 1, characterized in that, include: S1. Prepare perovskite / heterojunction tandem solar cell energy conversion unit, symmetrical supercapacitor energy storage unit and Janus symmetrical electrode respectively; S2. Stack the electrodes of the perovskite / heterojunction tandem solar cell energy conversion unit and the electrodes of the symmetrical supercapacitor energy storage unit on both sides of the Janus symmetrical electrode, place them in a mold, lead out the conductive ports, fill with epoxy resin, and dry to obtain an integrated photoelectric capacitor. The specific steps involved in fabricating the energy conversion unit for a perovskite / heterojunction tandem solar cell include: a. Surface texturing and damage removal of n-type single-crystal silicon substrates; b. Depositing intrinsic amorphous silicon thin films on both sides of an n-type monocrystalline silicon layer; c. Deposit a LiF thin film on the intrinsic amorphous silicon thin film on the first side; d. Metallic Mg was deposited on LiF thin films by thermal evaporation, followed by post-annealing at 120 °C to form an electron-selective mixed film layer; e. Deposit Ag on the electron-selective mixed film to obtain a metal electrode; f. Depositing MoO on the intrinsic amorphous silicon thin film on the second side x As a hole-selective transport layer; g. Deposit a first IZO transparent conductive film as a composite junction on the hole selective transport layer; h. Spin-coat the prepared SnO2 colloidal solution onto the composite junction at a speed of 3500 rpm; i. A TiO2 colloidal solution is spin-coated onto the SnO2 layer at a speed of 4000 rpm to form an electron transport layer; j. A perovskite thin film is deposited on the electron transport layer by an anti-solvent spin coating process to form a perovskite light-absorbing layer; k. Spin-coating a spiro-OMeTAD layer as a hole transport layer; l. A second IZO transparent conductive film is deposited on the hole transport layer by magnetron sputtering; m. Silver grid lines are fabricated on the second IZO transparent conductive film as conductive ports to obtain a perovskite / doped heterojunction tandem solar cell energy conversion unit; The specific steps involved in fabricating a symmetrical supercapacitor energy storage unit include: ①. Oxidize flake graphite with an oxidizing agent, transfer the oxidized precipitate to a vacuum freeze dryer and freeze for 6-8 hours to obtain soft graphene oxide; ②. The obtained graphene oxide was prepared into graphene powder by thermal exfoliation, and then the thermally exfoliated graphene powder was activated by chemical method with KOH. ③. The activated graphene powder is uniformly mixed with a 5% (w / w) polytetrafluoroethylene aqueous solution to obtain a graphene paste; ④. Press the graphene paste into a thin film using a 0.5 MPa roller press, and then dry it in a vacuum oven at 70 °C to obtain a graphene electrode; ⑤. Press two identical graphene electrodes into a 200-mesh copper mesh, leaving a 1 mm gap between them, and fix them with epoxy resin; ⑥. Fill the gap between the two graphene electrodes with Na2SO4 electrolyte; ⑦. Seal the prepared device to obtain a symmetrical supercapacitor energy storage unit; The fabrication of Janus symmetric electrodes specifically includes: 1) Clean the copper foil in an ultrasonic generator for 15 minutes; 2) Apply a thin layer of conductive silver paste to both sides of the copper foil; 3) Place the copper foil coated with conductive silver paste into an oven and dry it to obtain the Janus symmetric electrode.

3. The method for fabricating an integrated photocapacitor according to claim 2, characterized in that, In S2, the electrodes of the perovskite / heterojunction tandem solar cell energy conversion unit and the electrodes of the symmetrical supercapacitor energy storage unit are connected through Janus symmetrical electrodes, placed in a mold, conductive ports are led out, epoxy resin is filled, and dried and cured at 75 ℃ for 30 minutes to obtain an integrated photoelectric capacitor.

4. The method for fabricating an integrated photocapacitor according to claim 2, characterized in that, The preparation of TiO2 colloidal solution involves: slowly adding 7 ml of oleic acid to 20 ml of cyclohexane under stirring at room temperature, then adding 5 ml of octadecylamine and 1 ml of tetrabutyl titanate, and then adding the mixed solution to a 50 ml autoclave and reacting at 180 °C for 24 hours; after cooling to room temperature, mixing the product with 200 ml of anhydrous ethanol and centrifuging, collecting the precipitate, and redispersing the precipitate in 24 ml of toluene to obtain a stable TiO2 colloidal solution.

5. The method for fabricating an integrated photocapacitor according to claim 2, characterized in that, The preparation of the perovskite light-absorbing layer specifically includes: adding a solution of 1.47 M PbI2, 0.11 M PbBr2, 1.4 M FAI, 0.11 M MABr and 0.5 M MACl to a mixed solvent system of DMSO / DMF, stirring at 70 ℃ for 1 hour to obtain a PVK precursor solution; spin-coating the PVK precursor solution onto a TiO2 layer, first at a speed of 1000 rpm for 10 s, then at a speed of 6000 rpm for 20 s, and dropping 140 μL of chlorobenzene solution onto the spin-coating substrate 5 s before the end of spin-coating, annealing the obtained film at 100 ℃ for 45 min, finally obtaining a perovskite light-absorbing layer with a film thickness of 600 nm.

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