Interface regulation and preparation method of tin-based perovskite solar cell
By employing a 2-10 nm thick Ni or Sn metal functional layer in tin-based perovskite solar cells, the problems of Sn2+ oxidation and energy level mismatch are solved, achieving efficient interface optimization and improved stability, making them suitable for industrial applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-04-07
AI Technical Summary
Tin-based perovskite solar cells suffer from problems such as Sn2+ being easily oxidized to Sn4+, leading to an increase in carrier recombination centers, energy level mismatch between the metal electrode and the perovskite/electron transport layer, and poor interface contact, resulting in nonradiative recombination losses and poor device stability.
By employing a Ni or Sn metal functional layer with a thickness of 2-10 nm, Sn2+ oxidation is suppressed through reduction, and the generated oxide forms a compatible transition structure with the hole transport layer, optimizing the interface contact. Furthermore, the formation of carrier recombination centers is avoided by matching the energy levels of the thin metal layer with the perovskite layer.
It improves carrier extraction efficiency, increases device photoelectric conversion efficiency by 3-6 times, enhances device stability compared to organic modification schemes, and reduces cost to 1/50-1/30 of Au, making it suitable for industrialization.
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Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the technical field of solar cells, in particular to interface regulation and preparation of a tin-based perovskite solar cell. BACKGROUND
[0002] The tin-based perovskite material is considered to be an ideal alternative material of the lead-based perovskite because of low toxicity, environmental friendliness and high theoretical photoelectric conversion efficiency (more than 30%). 2+ The Sn 4+ is easy to be oxidized into Sn 2+ , which increases the carrier recombination center.
[0003] The energy level of the metal electrode and the perovskite / electron transport layer is not matched, which causes low carrier extraction efficiency.
[0004] The interface contact is poor, which causes non-radiative recombination loss and poor device stability. SUMMARY
[0005] To solve the above technical problems, the application provides the following technical scheme.
[0006] The application provides interface regulation of a tin-based perovskite solar cell, which comprises, from bottom to top, a conductive substrate, a hole transport layer, a metal functional layer, a tin-based perovskite absorption layer, an electron transport layer and a metal counter electrode.
[0007] The hole transport layer is a NiO x or SnO2 film, and the metal functional layer is a Ni or Sn metal film with a thickness of 2-10 nm, which is directly deposited on the surface of the hole transport layer. 2+ The metal functional layer inhibits Sn 4+ oxidation through reduction, and the oxide generated after oxidation forms a compatible transition structure with the hole transport layer.
[0008] As a preferred technical solution of the present application, the tin-based perovskite absorption layer includes but is not limited to FASnI3-based or CsSnI3-based perovskite, doped with 5-10 mol% SnF2, with a thickness of 300-350 nm, Sn 4+ content ≤3%.
[0009] As a preferred technical solution of the present application, the hole transport layer has a thickness of 20-50 nm: if it is NiO x , it is prepared by a homogenization nanoparticle solution method, with a work function of 4.8-5.0 eV; if it is SnO2, it is prepared by a sol-gel method, with a work function of 4.6-4.8 eV.
[0010] As a preferred technical solution of the present application, the metal functional layer has a thickness of preferably 3-7 nm, the Ni metal layer is prepared by an electron beam evaporation method, with an evaporation rate of 0.08-0.15 nm / s; the Sn metal layer has an evaporation rate of 0.1-0.2 nm / s, and the preparation process has a vacuum degree of ≤5×10 -4 Pa.
[0011] A preparation method of interface regulation of a tin-based perovskite solar cell, comprising the following steps:
[0012] (1) ITO / FTO substrate pretreatment; the ITO / FTO substrate is sequentially ultrasonically cleaned in deionized water, acetone and isopropanol for 15 minutes each, dried by nitrogen blowing, and then treated by ultraviolet ozone for 20 minutes to remove organic matter and enhance the surface hydroxyl activity.
[0013] (2) Solution preparation of NiO x or SnO2 hole transport layer and annealing; two options: ① NiO x layer: homogenized NiO x nanoparticle dispersion liquid (concentration 5-8 mg / mL) is spin-coated on the substrate at 4000 rpm, and a 35 nm thick dense film is formed after annealing at 180°C for 30 minutes; ② SnO2 layer: SnCl2·2H2O is dissolved in ethanol (concentration 0.1-0.2 mol / L), spin-coated at 4500 rpm, and a 30 nm thick film is formed after annealing at 200°C for 25 minutes.
[0014] (3) Electron beam evaporation to prepare a 2-10 nm thick Ni / Sn metal functional layer; in a nitrogen glove box or vacuum chamber, a Ni / Sn metal layer is deposited on the surface of the hole transport layer by electron beam evaporation method - the Ni layer has an evaporation rate of 0.08-0.15 nm / s and a thickness of 5 nm; the Sn layer has an evaporation rate of 0.1-0.2 nm / s and a thickness of 7 nm, and the vacuum degree is ≤5×10 -4 Pa.
[0015] (4) Anti-solvent assisted spin-coating to prepare tin-based perovskite absorption layer; FAI / CsI, SnI2 and SnF2 are dissolved in DMF and DMSO mixed solvent (volume ratio 4:1) at a molar ratio of 1:1:0.08 to prepare a 1.2 mol / L precursor solution; spin-coating on the metal functional layer at 5000 rpm, drop anti-solvent chlorobenzene at 15 seconds, and annealing at 100℃ for 10 minutes to form a dense absorption layer.
[0016] (5) C 60 / BCP electron transport layer prepared by thermal evaporation; the sample is transferred to a vacuum evaporation chamber, and C 60 (30 nm) and BCP (5 nm) are sequentially thermal evaporated at an evaporation rate of 0.1 nm / s and 0.05 nm / s, respectively.
[0017] (6) Ag counter electrode is thermal evaporated and packaged. Continue to thermal evaporate Ag layer (100 nm) under vacuum condition to complete device packaging.
[0018] As a preferred technical solution of the present application, the molar ratio of FAI / CsI, SnI2 and SnF2 in the perovskite precursor solution in step (4) is 1:1:0.05-0.1, and the solvent is a mixed solution of DMF and DMSO with a volume ratio of 3-5:1.
[0019] As a preferred technical solution of the present application, the molar ratio of FAI / CsI, SnI2 and SnF2 in the perovskite precursor solution in step (4) is 1:1:0.05-0.1, and the solvent is a mixed solution of DMF and DMSO with a volume ratio of 3-5:1. x The preparation of the hole transport layer uses homogeneous NiO x nanoparticle dispersion solution (concentration 5-8 mg / mL) is spin-coated and annealed at 180℃ for 25-35 minutes; SnO2 hole transport layer is spin-coated using SnCl2·2H2O ethanol solution (0.1-0.2 mol / L) and annealed at 200℃ for 20-30 minutes.
[0020] The present application has the following beneficial effects:
[0021] I. Interface regulation and preparation method of the tin-based perovskite solar cell, the metal functional layer (Ni / Sn) is preferentially reacted with oxygen or Sn 4+ in the system (such as Ni+Sn 4+ = Ni 2+ + Sn 2+ ), directly inhibits Sn 2+ oxidation, and the amount of Sn 4+ generated is reduced by more than 55%; at the same time, the NiO x / SnO2 generated after the metal is oxidized forms a lattice matching structure (NiO x -NiO x lattice mismatch degree <2%) with the substrate transport layer, avoiding the generation of interface defects.
[0022] II. The interface regulation and preparation method of the tin-based perovskite solar cell, the thickness of the 2-10 nm thin metal layer is only 1 / 3-1 / 10 of the traditional metal electrode, and the formation of a carrier trapping center is avoided; in cooperation with the energy level buffer effect of the transition layer after oxidation (for example, Sn metal is oxidized to form SnO2, which can realize the energy level connection of NiO x (4.9eV) and perovskite (5.4eV)), and the hole extraction efficiency is improved.
[0023] III. The interface regulation and preparation method of the tin-based perovskite solar cell, based on the Ni / NiO x interface, the photoelectric conversion efficiency of the device reaches 12.3% (0.074cm 2 ), and the efficiency of the device based on the Sn / SnO2 interface reaches 11.11%, which is 3-6 times higher than that of the control group without a metal layer (2.87%); the initial efficiency of the unsealed device is maintained above 85% after aging for 500 hours, which is better than the organic modification scheme.
[0024] IV. The interface regulation and preparation method of the tin-based perovskite solar cell, the metal layer preparation is compatible with the existing vacuum evaporation equipment, the hole transport layer can be prepared by a solution method, and the cost of Ni / Sn metal is only 1 / 50-1 / 30 of that of Au, which is suitable for industrialization and popularization. BRIEF DESCRIPTION OF DRAWINGS
[0025] The accompanying drawings are used to provide a further understanding of the present application, and constitute a part of the specification, together with the embodiments of the present application, to explain the present application, and do not constitute a limitation of the present application. In the drawings:
[0026] Figure 1 is a method flow chart of the interface regulation and preparation method of the tin-based perovskite solar cell of the present application;
[0027] Figure 2 is a typical structure schematic diagram of the tin-based perovskite solar cell of the present application;
[0028] Figure 3 is the UPS data of NiOx in Example 1 of the present application, and the work function is about 4.98eV.
[0029] Figure 4 is the XPS data of the Sn-based perovskite deposited on NiOx in Example 1 of the present application, wherein 44 is the XPS data of the Sn-based perovskite deposited on NiOx without a Ni layer; and 41-43 are the XPS data of the Sn-based perovskite deposited on NiOx after depositing a Ni layer.
[0030] Figure 5 is the J-V data related to Example 1 of the present application.
[0031] Figure 6These are JV data related to Example 2 of the present invention, wherein the thicknesses of the Sn layer are 0, 2, 5, 7 and 10 nm, respectively. Detailed Implementation
[0032] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.
[0033] Example 1:
[0034] like Figure 1 As shown, an interface modulation method for a tin-based perovskite solar cell includes, from bottom to top, a conductive substrate, a hole transport layer, a metal functional layer, a tin-based perovskite absorber layer, an electron transport layer, and a metal counter electrode.
[0035] The hole transport layer is NiO. x The thin film, the metal functional layer is a Ni metal thin film, which is prepared by electron beam evaporation at an evaporation rate of 0.1 nm / s and directly deposited on the surface of the hole transport layer with a thickness of 5 nm.
[0036] The tin-based perovskite absorber layer is FASnI3 perovskite, doped with 10 mol% SnF2.
[0037] The preparation method is as follows:
[0038] (1) Pretreatment of ITO / FTO substrates;
[0039] (2) Solution preparation of NiO x Hole transport layer and annealing;
[0040] (3) Electron beam evaporation was used to prepare a 5 nm thick Ni metal functional layer;
[0041] (4) Preparation of tin-based perovskite absorber layer by anti-solvent-assisted spin coating;
[0042] (5) Preparation of C by thermal evaporation 60 / BCP electronic transport layer;
[0043] (6) Hot-dip evaporation of Ag counter electrode and encapsulation.
[0044] In step (4), the molar ratio of FAI, SnI2 and SnF2 in the perovskite precursor solution is 1:1:0.1, and the solvent is a mixture of DMF and DMSO with a volume ratio of 4:1.
[0045] NiO in step (2) x The hole transport layer was fabricated using homogenized NiO. x Spin-coating of nanoparticle dispersion (concentration 8 mg / mL) and annealing at 180°C for 30 minutes.
[0046] The specific steps are as follows: ITO glass is ultrasonically cleaned with deionized water, acetone, and isopropanol for 10 minutes in sequence, dried with nitrogen, and then treated with ultraviolet ozone for 30 minutes to remove organic matter and enhance the surface hydroxyl activity.
[0047] Homogenized NiO x Nanoparticle dispersion (6 mg / mL) was spin-coated at 4000 rpm for 30 seconds and annealed at 180°C for 30 minutes.
[0048] Electron beam evaporation of Ni layer at a rate of 0.1 nm / s, thickness of 5 nm, and vacuum level of 3 × 10⁻⁶. -4 Pa.
[0049] FAI, SnI2, and SnF2 (1:1:0.08 mol ratio) were dissolved in DMF / DMSO (4:1). The 1.2 mol / L solution was spin-coated at 5000 rpm for 40 seconds. At 15 seconds, 20 μL of chlorobenzene was added dropwise. The mixture was then annealed at 100 °C for 10 minutes to achieve a thickness of 320 nm.
[0050] C 60 Thermal evaporation of BCP (30nm) and BCP (5nm) was carried out at rates of 0.1nm / s and 0.05nm / s, respectively.
[0051] The Ag layer underwent thermal evaporation at a rate of 0.5 nm / s at a wavelength of 100 nm.
[0052] Device testing: photoelectric conversion efficiency 12.63%, open-circuit voltage 0.76V, short-circuit current density 21.85mA / cm². 2 The fill factor is 0.76; the efficiency retention rate is 86% after 500 hours of aging without encapsulation.
[0053] Example 2:
[0054] The hole transport layer was replaced with SnO2 (prepared with 0.15 mol / L SnCl2 ethanol solution, 30 nm thick), and the metal functional layer was Sn metal. Other basic parameters remained the same as in Example 1. Sn layer thicknesses of 2 nm, 5 nm, 7 nm, and 10 nm were set respectively. The results showed that the device efficiency was highest at 7 nm (11.11%), while at 2 nm, the reduction ability of Sn was insufficient. 4+ The content is still 4.3%, and the efficiency drops to 8.65% at 10nm (composite centers begin to form); therefore, the optimal thickness of the metal functional layer is 3-7nm, and the Sn / SnO2 interface device retains 89% efficiency after 1200 hours of illumination.
[0055] Comparative Example 1:
[0056] Remove the metal functional layer and directly apply it to NiO. xThe perovskite layer was prepared on the hole transport layer, and the other parameters were the same as in Example 1. The device efficiency was only 2.87%, the open circuit voltage was 0.31 V, Sn 4+ The content reached 5.8%, the efficiency retention rate after 100 hours of storage was only 65%; and the carrier recombination rate at the interface was 3.2 times that of the device of the present application, verifying the dual role of the metal functional layer of "inhibiting oxidation + optimizing the interface".
[0057] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and not for limiting the present application, although the foregoing detailed description of the present application is made with reference to the foregoing examples, for those skilled in the art, it still can be modified, or part of the technical features of the equivalent replacement of the technical solutions recorded in the foregoing examples. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application.
Claims
1. An interface modulation method for a tin-based perovskite solar cell, characterized in that, It includes, from bottom to top, a conductive substrate, a hole transport layer, a metal functional layer, a tin-based perovskite absorber layer, an electron transport layer, and a metal counter electrode; The hole transport layer is NiO. x Alternatively, a SnO2 thin film may be used, wherein the metal functional layer is a Ni or Sn metal thin film with a thickness of 2-10 nm, which is directly deposited on the surface of the hole transport layer. The metal functional layer inhibits Sn through reduction. 2+ Oxidation, the resulting oxides form a compatible transition structure with the hole transport layer.
2. The interface modulation of a tin-based perovskite solar cell according to claim 1, characterized in that, The tin-based perovskite absorber layer comprises, but is not limited to, FASnI3-based or CsSnI3-based perovskite, doped with 5-10 mol% SnF2, and has a thickness of 300-350 nm. 4+ Content ≤3%.
3. The interface modulation of a tin-based perovskite solar cell according to claim 1, characterized in that, The hole transport layer has a thickness of 20-50 nm: if it is NiO x The homogenized nanoparticle solution method is used for preparation, with a work function of 4.8-5.0 eV; if SnO2 is used, the sol-gel method is used for preparation, with a work function of 4.6-4.8 eV.
4. The interface modulation of a tin-based perovskite solar cell according to claim 1, characterized in that, The thickness of the metal functional layer is preferably 3-7 nm. The Ni metal layer is prepared by electron beam evaporation at a rate of 0.08-0.15 nm / s; the Sn metal layer has an evaporation rate of 0.1-0.2 nm / s, and the vacuum degree during the preparation process is ≤5×10⁻⁶. -4 Pa.
5. A method for interface control in the fabrication of a tin-based perovskite solar cell, applied to the interface control of a tin-based perovskite solar cell according to any one of claims 1-4, characterized in that, Includes the following steps: (1) Pretreatment of ITO / FTO substrates; (2) Solution preparation of NiO x Or SnO2 hole transport layer and annealing; (3) Electron beam evaporation was used to prepare 2-10 nm thick Ni / Sn metal functional layers; (4) Preparation of tin-based perovskite absorber layer by anti-solvent-assisted spin coating; (5) Preparation of C by thermal evaporation 60 / BCP electronic transport layer; (6) Hot-dip evaporation of Ag counter electrode and encapsulation.
6. The interface control and fabrication method of a tin-based perovskite solar cell according to claim 1, characterized in that, In step (4), the molar ratio of FAI / CsI, SnI2 and SnF2 in the perovskite precursor solution is 1:1:0.05-0.1, and the solvent is a mixture of DMF and DMSO with a volume ratio of 3-5:
1.
7. The interface control and preparation method of a tin-based perovskite solar cell according to claim 1, characterized in that, NiO in step (2) x The hole transport layer was fabricated using homogenized NiO. x Nanoparticle dispersion (concentration 5-8 mg / mL) was spin-coated and annealed at 180℃ for 25-35 minutes; SnO2 hole transport layer was spin-coated with SnCl2·2H2O ethanol solution (0.1-0.2 mol / L) and annealed at 200℃ for 20-30 minutes.