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CN-121974958-A - Preparation of fluorine-rich gold-silver nanocluster and application of fluorine-rich gold-silver nanocluster in aspect of improving perovskite solar cell performance

CN121974958ACN 121974958 ACN121974958 ACN 121974958ACN-121974958-A

Abstract

The invention discloses a preparation method of an atomic-level accurate halogen-fluorine-containing mercaptan co-protected gold and silver nanocluster and application of the gold and silver nanocluster in a perovskite solar cell. The molecular formula of the nanocluster is [ Au12Ag30 (SPh ( 3,5‑ CF 3) 2) 10Br20] (PPh 4) 6, and the preparation method comprises the steps of reacting fluorine-containing mercaptan ligand HSPh ( 3,5‑ CF 3) 2 with chloroauric acid and silver nitrate in a mixed solvent of methanol and dichloromethane, reducing the mixture by sodium borohydride, adding tetraphenyl phosphonium bromide, and obtaining black bulk crystals by diffusion crystallization in a dichloromethane/normal hexane system. The cluster has a unique cake-shaped structure, the inner core of the cluster is an Au12 icosahedron and is wrapped by an Ag30 atom shell layer, a {100} crystal face is densely covered by 20 Br-ligands, 10 thiol ligands containing-CF 3 form a hydrophobic ring belt at the waist of the cluster, and the surface halogen coverage rate is as high as 66.7%. The clusters are used as additives to be introduced into an electron transport layer of the perovskite solar cell, so that interface defects can be effectively passivated, moisture invasion can be restrained, and the photoelectric conversion efficiency and the environmental stability of the perovskite solar cell are remarkably improved.

Inventors

  • Zhang Zhenmo
  • MA ALONG
  • WU ZHANCHAO
  • WANG SHUXIN

Assignees

  • 青岛科技大学

Dates

Publication Date
20260505
Application Date
20260128

Claims (10)

  1. 1. An atomically precise halogen-fluorine-containing mercaptan co-protected gold and silver nanocluster is characterized by having a molecular formula of [ Au 12 Ag 30 (SPh(3,5-CF 3 ) 2 ) 10 Br 20 ](PPh 4 ) 6 ] wherein a ligand SPh (3, 5-CF 3 ） 2 is 3, 5-bis (trifluoromethyl) thiophenol; the nanocluster has an atomically precise structure, a core of which is an Au 12 icosahedron, the core is wrapped by an Ag 30 atomic shell, 20 Br-ligands are arranged on {100} crystal planes at two ends of the Ag 30 shell, and 10 SPh (3, 5-CF 3 ） 2 ligands are arranged at the waist of the Ag 30 shell and form a hydrophobic protective belt).
  2. 2. The gold and silver nanocluster according to claim 1, characterized in that the Ag 30 shell layer is composed of six atomic layers, in order of L1, L2, L3, L1', L2' and L3 '.
  3. 3. The gold and silver nanocluster according to claim 1, characterized in that the surface halogen atom coverage of the nanocluster is 66.7%.
  4. 4. A method of preparing gold and silver nanoclusters according to any of claims 1 to 3, characterized by the steps of: Dissolving chloroauric acid and silver nitrate in a mixed solvent consisting of methanol and dichloromethane to obtain a mixed solution; adding 3, 5-bis (trifluoromethyl) thiophenol as a ligand into the mixed solution, and stirring for coordination reaction; Under the condition of intense stirring, adding an ice water solution of sodium borohydride into a reaction system for reduction reaction; After the reduction reaction is finished, adding tetraphenyl phosphonium bromide into the system, and continuously stirring; Concentrating, precipitating, centrifuging and washing the reacted solution to obtain a crude product; and dissolving the crude product in dichloromethane, and performing liquid phase diffusion crystallization by adopting normal hexane to obtain the black gold and silver nanocluster monocrystal.
  5. 5. The method of claim 4, wherein the chloroauric acid is provided as HAuCl 4 ·3H 2 O.
  6. 6. The method of claim 4, wherein the sodium borohydride is added in excess.
  7. 7. Use of gold and silver nanoclusters according to any of claims 1 to 3 as an additive in perovskite solar cells.
  8. 8. The use according to claim 7, wherein the gold and silver nanoclusters are added to a perovskite precursor solution for the preparation of a perovskite electron absorbing layer.
  9. 9. The use according to claim 8, wherein the gold and silver nanoclusters are added to the perovskite precursor solution at a concentration of 0.1-1.0 mg/mL.
  10. 10. A perovskite solar cell, characterized in that a perovskite light absorbing layer is doped with gold and silver nanoclusters according to any one of claims 1 to 3.

Description

Preparation of fluorine-rich gold-silver nanocluster and application of fluorine-rich gold-silver nanocluster in aspect of improving perovskite solar cell performance Technical Field The invention relates to the technical field of nano materials and photoelectric devices, in particular to a gold-silver alloy nanocluster (Nanocluster) with accurate atomic level, specific geometric structure and surface chemical characteristics, a preparation method thereof and application of the gold-silver alloy nanocluster serving as a functional additive in improving the photoelectric conversion efficiency and environmental stability of a perovskite solar cell (Perovskite Solar Cells). Background Perovskite solar cells are a research hotspot due to their high Photoelectric Conversion Efficiency (PCE) and low manufacturing costs. However, the commercialization process still faces two key challenges, namely firstly, a perovskite film can generate a large number of intrinsic defects (such as lead vacancies, iodine vacancies and uncomplexed Pb < 2+ > ions) in the crystallization process, the defects can become non-radiative recombination centers of carriers, and thus voltage and efficiency losses are caused, and secondly, perovskite materials are extremely sensitive to environmental moisture, oxygen and the like, so that devices are rapidly degraded, and the stability is insufficient. At present, additive engineering strategies are often employed to solve the above problems, such as the introduction of halogen salts (e.g., pbBr 2, MABr) to deactivate ion defects, or the introduction of hydrophobic molecules (e.g., long chain alkylammonium salts, fluorochemicals) to promote moisture resistance. However, the simple mixing of these small molecule additives with single functions may lead to problems of complex formulation of precursor solution, uneven distribution of components, phase separation, formation of discontinuous modification layer at perovskite grain boundary, and the like, and instead introduces new instability factors. Therefore, there is an urgent need in the art to develop a novel multifunctional integrated additive capable of simultaneously realizing efficient defect passivation and strong environmental shielding without affecting charge transfer, thereby synergistically improving the efficiency and stability of perovskite solar cells. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a gold-silver nanocluster additive which has the dual functions of defect passivation and humidity resistance and is accurate in structure, a preparation method thereof and application thereof in perovskite solar cells. In order to achieve the above purpose, the invention adopts the following technical scheme: in a first aspect, the present invention provides a halogen-fluorothiol co-protected gold and silver nanocluster having the formula [ Au 12Ag30(SPh(3,5-CF3)2)10Br20](PPh4)6 ], wherein the SR ligand is 3, 5-bis (trifluoromethyl) thiophenol. The cluster has an atomic-level accurate structure, is in an anisotropic cake-shaped or wheel-shaped geometric configuration as a whole, and is characterized in that: 1. the inner core is an icosahedron (Au 12) composed of 12 gold atoms; 2. The Au 12 core is wrapped by an Ag 30 shell layer which consists of 30 silver atoms and is divided into six layers (L1, L2, L3, L1', L2', L3 '); 3.20 bromine (Br) ligands are densely allocated on {100} crystal faces at two ends of the Ag 30 shell layer, and the coverage rate of surface halogen atoms is as high as 66.7%; 4.10 of the thiol ligands containing-CF 3 were precisely located at the waist of the Ag 30 shell, forming a continuous, highly hydrophobic annular guard band. In a second aspect, the present invention provides a method for preparing the gold and silver nanoclusters, including the steps of: s1, dissolving chloroauric acid (HAuCl 4·3H2 O) and silver nitrate (AgNO 3) in a mixed solvent consisting of methanol and dichloromethane, and stirring and mixing uniformly; S2, adding ligand 3, 5-bistrifluoromethyl thiophenol (HSPh (3, 5-CF 3）2) into the solution, and continuously stirring to carry out coordination reaction; S3, rapidly adding an excessive sodium borohydride (NaBH 4) ice water solution under intense stirring to carry out reduction reaction; s4, after the reduction reaction is finished, adding tetraphenyl phosphonium bromide (PPh 4 Br) into the system, and continuously stirring; s5, performing rotary evaporation concentration on the reacted crude product solution, removing part of solvent, adding a poor solvent (such as n-hexane) for precipitation and centrifugal separation, and washing the obtained solid with an organic solvent; And S6, dissolving the washed product in dichloromethane, slowly diffusing n-hexane into the solution by adopting a liquid phase diffusion method, standing and crystallizing at room temperature, and finally obtaining the black [Au12Ag30(SPh(3,5-CF3)2)10Br20](PPh4)6 na