A 1-phenylacetylacetone chelate, a preparation method thereof and an application thereof

Abstract

The present invention relates to the technical field of polymer solar cells, and particularly to a 1-phenylacetylacetone chelate, a preparation method thereof and an application. The 1-phenylacetylacetone chelate has the structure shown in formula (I). In formula (I), M is selected from any metal element in Group IIIA or any metal element in Group IVB. By using the 1-phenylacetylacetone chelate as a material for the electron transport layer and applying it to a polymer solar cell device, compared with other electron transport layers, the 1-phenylacetylacetone chelate can form a certain hemispherical structure on the surface of the active layer while having excellent transport ability, increasing the optical path of incident light. At the same time, after reasonably adjusting the thickness, the maximum light intensity in the device is located at the position of the active layer, strengthening the light absorption of the active layer, thereby improving the exciton generation rate and the short-circuit current density and photoelectric conversion efficiency of the battery device.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer solar cells, and in particular to a 1-phenylacetylacetone chelate, a preparation method thereof, and an application thereof. Background Art

[0002] In the past few years, organic polymer-based solar cells have attracted extensive attention from researchers due to their low cost, material and functional diversity. Due to innovations in material design and device structure, the certified power conversion efficiencies (PCEs) of the best single-junction polymer solar cells (PSCs) have now reached 17.4%. In traditional organic polymer solar cell devices, the organic active layer that absorbs photons is placed between the hole transport layer (HTL) and the electron transport layer (ETL). As a bridge for carrier transport between the active layer and the electrode, the transport layer must have good electron or hole transport properties, form a good ohmic contact with the electrode, and minimize recombination losses.

[0003] For organic polymer solar cells, due to the short exciton diffusion length and low carrier mobility of most organic semiconductor materials, the optimal thickness of the photoactive layer of non-fullerene PSCs is generally around 100 nm, which is much thinner than the ideal thickness that can completely absorb incident light. Therefore, how to improve the light collection performance of the bulk heterojunction (BHJ) with a fixed thickness is the key to improving device performance. However, most methods for improving the light absorption of BHJ by modifying the active layer are often complex in process and high in cost. Therefore, researchers have turned their attention to the improvement of the transport layer, which is simpler and more effective in process.

[0004] The transport layer in a battery device is generally used as a medium for exciton transport, transports electrons or holes according to materials with different work functions, forms a good ohmic contact at the interface, reduces recombination losses, and thus improves device performance. In addition, the interfacial material can also greatly prevent the contamination of the active layer by the diffusion of electrode materials, including replacing moisture- and oxygen-sensitive low-work-function metals such as Ca, Ba, and Mg, thereby greatly improving the stability of the device. Finally, the transport layer can improve the light absorption of the active layer, including increasing the optical path of incident light and affecting the distribution of the light field in the device. When a beam of light irradiates the surface of the active layer through a transparent electrode, light reflection, absorption, scattering, and transmission will occur and will ultimately be reflected by the reflective metal electrode. Therefore, when the incident light meets the reflected light from the metal electrode, light interference may occur, and a standing wave can be formed in the device, resulting in a redistribution of the light intensity in the device. Reasonable regulation of the interfacial layer material will increase the light absorption of the active layer, promote carrier generation, and thus improve the efficiency of the battery device.

[0005] In traditional forward polymer battery devices, the light intensity at the interface between the photoactive layer and the reflective electrode is the weakest (close to zero). In order to improve the utilization rate of incident light and the performance of the device, it is necessary to control the strongest light intensity distribution by selecting an interface material with an appropriate refractive index. Therefore, it is particularly important to develop a new type of electron transport layer material to enhance the light intensity distributed in the active layer, thereby increasing the short-circuit current density and improving the device performance. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a 1-phenylacetylacetone chelate, its preparation method and application. Using the 1-phenylacetylacetone chelate of the present invention as a material for the electron transport layer can increase the short-circuit current density and the photoelectric conversion efficiency of the battery device.

[0007] The present invention provides a 1-phenylacetylacetone chelate having the structure shown in formula (I):

[0008] (I);

[0009] In formula (I), M is selected from any metal element in Group IIIA or any metal element in Group IVB.

[0010] Preferably, the M is selected from Al, Ga, In, Ti, Zr or Hf.

[0011] The present invention also provides a preparation method of a 1-phenylacetylacetone chelate, comprising the following steps:

[0012] Dissolve a ligand compound having the structure shown in formula (II) and a chloride of M in an ethanol solution, and stir at 65-75 °C to obtain a 1-phenylacetylacetone chelate having the structure shown in formula (I): M is selected from any metal element in Group IIIA or any metal element in Group IVB;

[0013] (I); (II).

[0014] Preferably, the ligand compound having the structure shown in formula (II) is prepared according to the following method:

[0015] a) Mix acetophenone and ethyl acetate to obtain a first mixed solution;

[0016] b) Under the condition of an ice-water bath, add sodium amide dropwise to the first mixed solution and react to obtain a white precipitate;

[0017] c) Mix the white precipitate, water and hydrochloric acid solution, and after filtration, the obtained precipitate is recrystallized and dried to obtain a ligand compound having the structure shown in formula (II).

[0018] The present invention also provides a polymer solar cell device, comprising:

[0019] A glass substrate (1) with an ITO coating;

[0020] A hole transport mesa (2) is compounded on one side of the glass substrate with the ITO coating; a first metal electrode (5) is also provided on one side of the glass substrate with the ITO coating;

[0021] An active mesa (3) is compounded on the hole transport mesa;

[0022] An electron transport mesa (4) is compounded on the active mesa;

[0023] A second metal electrode (6), a third metal electrode (7), a fourth metal electrode (8) and a fifth metal electrode (9) are provided on the electron transport mesa;

[0024] The electron transport mesa (4) comprises the 1-phenylacetylacetone chelate.

[0025] Preferably, the thickness of the ITO coating in the glass substrate (1) with the ITO coating is 170 - 180 nm;

[0026] The thickness of the hole transport mesa (2) is 20 - 30 nm;

[0027] The thickness of the active mesa (3) is 100 - 150 nm;

[0028] The thickness of the electron transport mesa (4) is 8 - 14 nm.

[0029] The present invention also provides a preparation method of the polymer solar cell device described above, comprising the following steps:

[0030] A) Spin-coat PEDOT:PSS on one side of the glass substrate (1) with the ITO coating, and after annealing, a hole transport layer (2') is obtained;

[0031] B) Under a nitrogen atmosphere, stir and dissolve the donor material PM6, the acceptor material Y6 and chloroform, mix the obtained solution with 1-chloronaphthalene, obtain an active solution, and drop-coat it on the hole transport layer, and after annealing, an active layer (3') is obtained;

[0032] C) Spin-coat an ethanol solution of the 1-phenylacetylacetone chelate on the active layer, and after drying, an electron transport layer (4') is obtained;

[0033] D) Under a nitrogen atmosphere, use a scraper to scrape off the electron transport layer, active layer, and electron and hole transport layer at one end of the device obtained in step C), exposing a part of the glass substrate with an ITO coating to obtain a hole transport mesa (2), an active mesa (3), and an electron transport mesa (4);

[0034] E) Under a vacuum of less than 5×10 -4 Pa, evaporate and deposit a metal electrode on the exposed glass substrate with an ITO coating and the electron transport mesa (4) to obtain a first metal electrode (5), a second metal electrode (6), a third metal electrode (7), a fourth metal electrode (8), and a fifth metal electrode (9).

[0035] Preferably, the glass substrate (1) with an ITO coating is prepared according to the following method:

[0036] Cover a layer of ITO on the glass substrate through a sputtering process, and successively pass through a detergent ultrasonic bath, an ultrapure water ultrasonic bath, an acetone ultrasonic bath, and an ethanol ultrasonic bath, and then perform ultraviolet ozone treatment to obtain an ITO layer;

[0037] In step A), the annealing temperature is 145~155 °C, and the annealing time is 13~18 min.

[0038] Preferably, in step B), the mass ratio of the donor material PM6 to the acceptor material Y6 is 1:1.2;

[0039] For the obtained solution, the contents of the donor material PM6 and the acceptor material Y6 are 15~17 mg / mL;

[0040] The annealing temperature is 105~115 °C, and the annealing time is 8~12 min.

[0041] Preferably, in step C), the concentration of the ethanol solution of 1-phenylacetylacetone chelate is 0.8~1.2 mg / mL;

[0042] The rotation speed of the spin coating is 2000~4500 rpm, and the spin coating time is 30 s.

[0043] The present invention provides a 1-phenylacetylacetone chelate having the structure shown in formula (I). In formula (I), M is selected from any metal element in Group IIIA or any metal element in Group IVB. By using the 1-phenylacetylacetone chelate as the material of the electron transport layer and applying it to a polymer solar cell device, compared with other electron transport layers, the 1-phenylacetylacetone chelate can form a certain hemispherical structure on the surface of the active layer while having excellent transport ability, increasing the optical path of the incident light. At the same time, after reasonably regulating the thickness, the maximum light intensity in the device is located at the position of the active layer, strengthening the light absorption of the active layer, thereby improving the exciton generation rate and increasing the short-circuit current density and photoelectric conversion efficiency of the battery device. In addition, while improving the current of the device, this material does not change the thickness of the active layer, ensuring both the transport of carriers and the increase of the current density of the device. Moreover, from the perspective of process preparation, the improvement of the light absorption of the active layer is achieved only through solution preparation. The polymer solar cell device does not need to adopt an optical spacer layer and an optical microcavity structure, reducing the complexity of the preparation process compared with adding an optical spacer layer and an optical microcavity structure, and reducing the energy consumption compared with the method of preparing a thin film by magnetron sputtering. It has simple operation and remarkable effects and is suitable for large-scale commercial production.

[0044] The experimental results show that the device prepared by the present invention has a short-circuit current density greater than 25.4 mA / cm 2 under the simulated solar light irradiation of 100 mW / cm 2 , and the photoelectric conversion efficiency is not less than 15.70%. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic structural diagram of a polymer solar cell device provided by an embodiment of the present invention;

[0046] Figure 2 It is a schematic structural diagram of the device obtained in step C) provided by an embodiment of the present invention;

[0047] Figure 3 It is an energy level diagram of a polymer solar cell device prepared in Example 3 of the present invention;

[0048] Figure 4 It is an AFM diagram of a polymer solar cell device prepared in Example 3 of the present invention;

[0049] Figure 5 It is a current density-voltage curve of the polymer solar cell devices prepared in Examples 3 to 6 and Comparative Example 1 of the present invention under the simulated solar light irradiation of 100 mW / cm 2 ;

[0050] Figure 6It is the external quantum efficiency curve graph of the polymer solar cell devices prepared in Examples 3-6 and Comparative Example 1 of the present invention;

[0051] Figure 7 It is |E(x)| of the polymer solar cell device prepared in Example 3 of the present invention 2 The simulated distribution diagrams under irradiation at 380 nm, 480 nm, 580 nm and 680 nm;

[0052] Figure 8 It is the simulated distribution diagram of the exciton generation rate in the BHJ of the polymer solar cell device prepared in Example 3 of the present invention;

[0053] Figure 9 It is the current density-voltage curve of the polymer solar cell devices prepared in Examples 7-8 of the present invention under simulated sunlight of 100 mW / cm 2 ;

[0054] Figure 10 It is the external quantum efficiency curve graph of the polymer solar cell devices prepared in Examples 7-8 of the present invention. Detailed implementation manners

[0055] Next, in combination with the embodiments of the present invention, the technical solutions of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0056] The present invention provides a 1-phenylacetylacetone chelate having the structure shown in formula (I):

[0057] (I);

[0058] In formula (I), M is selected from any one of the metal elements in Group IIIA or any one of the metal elements in Group IVB.

[0059] In certain embodiments of the present invention, the M is selected from Al, Ga, In, Ti, Zr or Hf.

[0060] The present invention also provides a preparation method of the above-mentioned 1-phenylacetylacetone chelate, including the following steps:

[0061] Dissolve the ligand compound having the structure shown in formula (II) and the chloride of M in an ethanol solution, and stir at 65-75 °C to obtain a 1-phenylacetylacetone chelate having the structure shown in formula (I): M is selected from any one of the metal elements in Group IIIA or any one of the metal elements in Group IVB;

[0062] (I); (II).

[0063] In certain embodiments of the present invention, the ligand compound having the structure shown in formula (II) is prepared according to the following method:

[0064] a) Mix acetophenone with ethyl acetate to obtain a first mixed solution;

[0065] b) Under the condition of an ice-water bath, add sodium amide dropwise to the first mixed solution and react to obtain a white precipitate;

[0066] c) Mix the white precipitate, water and hydrochloric acid solution, filter, and the obtained precipitate is recrystallized and dried to obtain the ligand compound having the structure shown in formula (II).

[0067] In certain embodiments of the present invention, the dosage ratio of acetophenone to ethyl acetate is 5 g:200 mL.

[0068] In certain embodiments of the present invention, the molar ratio of sodium amide to acetophenone is 0.2 mol:0.042 mol.

[0069] In certain embodiments of the present invention, the dropping rate of sodium amide is 10 mL / min.

[0070] In certain embodiments of the present invention, in step b), the reaction temperature is 0-25 °C and the reaction time is 1 h. In certain embodiments, in step b), the reaction temperature is 25 °C.

[0071] In certain embodiments of the present invention, after the reaction in step b), filtration is further included. The present invention has no special limitation on the filtration method, and a filtration method well-known to those skilled in the art can be used.

[0072] After obtaining the white precipitate, mix the white precipitate, water and hydrochloric acid solution, filter, and the obtained precipitate is recrystallized and dried to obtain the ligand compound having the structure shown in formula (II).

[0073] The present invention has no special limitation on the amount of water used, as long as it can dissolve the white precipitate. In certain embodiments of the present invention, the mass fraction of the hydrochloric acid solution is 50%. In certain embodiments of the present invention, the molar ratio of hydrochloric acid to the white precipitate is 1:1. The role of hydrochloric acid is to adjust the pH of the reactants to obtain the target product.

[0074] The present invention places no special restrictions on the filtration method, and any filtration method well-known to those skilled in the art can be used. The present invention places no special restrictions on the recrystallization and drying methods, and any recrystallization and drying methods well-known to those skilled in the art can be used.

[0075] After obtaining the ligand compound having the structure shown in formula (II), the ligand compound having the structure shown in formula (II) and the chloride of M are dissolved in an ethanol solution and stirred at 65-75 °C to obtain a 1-phenylacetylacetone chelate having the structure shown in formula (I).

[0076] In certain embodiments of the present invention, the chloride of M is selected from AlCl3, GaCl3, InCl2, TiCl4, ZrCl4 or HfCl4. In certain embodiments, the chloride of M is HfCl4.

[0077] In certain embodiments of the present invention, the mass ratio of the ligand compound having the structure shown in formula (II) to the chloride of M is 5-6:0.8-1. In certain embodiments, the mass ratio of the ligand compound having the structure shown in formula (II) to the chloride of M is 6:1.

[0078] In certain embodiments of the present invention, the mass concentration of the ethanol solution is 95%-99%. In certain embodiments, the mass concentration of the ethanol solution is 99%.

[0079] In certain embodiments of the present invention, the stirring temperature is 65-75 °C. In certain embodiments, the stirring temperature is 70 °C. In certain embodiments, the stirring time is 12 h.

[0080] In certain embodiments of the present invention, after the stirring is completed, it further includes: washing the precipitate obtained from the stirring with methanol to obtain a 1-phenylacetylacetone chelate having the structure shown in formula (I). The function of methanol washing is to remove impurities such as reactants.

[0081] The present invention also provides a polymer solar cell device, including:

[0082] A glass substrate (1) with an ITO coating;

[0083] A hole transport mesa (2) is compounded on one side of the glass substrate with an ITO coating; a first metal electrode (5) is also provided on one side of the glass substrate with an ITO coating;

[0084] An active mesa (3) is compounded on the hole transport mesa;

[0085] An electron transport mesa (4) is compounded on the active mesa;

[0086] A second metal electrode (6), a third metal electrode (7), a fourth metal electrode (8), and a fifth metal electrode (9) are provided on the electron transport tabletop.

[0087] The electron transport tabletop (4) includes the 1-phenylacetylacetone chelate described above.

[0088] See Figure 1 , Figure 1 which is a schematic structural diagram of a polymer solar cell device provided by an embodiment of the present invention; wherein, 1 is a glass substrate with an ITO coating, 2 is a hole transport tabletop, 3 is an active tabletop, 4 is an electron transport tabletop, 5 is a first metal electrode, 6 is a second metal electrode, 7 is a third metal electrode, 8 is a fourth metal electrode, and 9 is a fifth metal electrode.

[0089] In certain embodiments of the present invention, the glass substrate (1) with an ITO coating is prepared by the following method:

[0090] A layer of ITO is covered on the glass substrate through a sputtering process, and then successively passed through a detergent ultrasonic bath, an ultrapure water ultrasonic bath, an acetone ultrasonic bath, and an ethanol ultrasonic bath, and then treated with ultraviolet ozone to obtain an ITO layer.

[0091] The present invention has no special limitations on the steps and parameters of the sputtering process, and the sputtering process steps and parameters well-known to those skilled in the art can be adopted.

[0092] In certain embodiments of the present invention, the detergent used in the detergent ultrasonic bath is dishwashing liquid. In certain embodiments of the present invention, the time of the detergent ultrasonic bath is 15 min. In certain embodiments, the ultrasonic frequency of the detergent ultrasonic bath is 40 KHz, and the power is 500 W. In certain embodiments of the present invention, the time of the ultrapure water ultrasonic bath is 15 min. In certain embodiments, the ultrasonic frequency of the ultrapure water ultrasonic bath is 40 KHz, and the power is 500 W. In certain embodiments of the present invention, the time of the acetone ultrasonic bath is 15 min. In certain embodiments, the ultrasonic frequency of the acetone ultrasonic bath is 40 KHz, and the power is 500 W. In certain embodiments of the present invention, the time of the ethanol ultrasonic bath is 15 min. In certain embodiments, the ultrasonic frequency of the ethanol ultrasonic bath is 40 KHz, and the power is 500 W.

[0093] In certain embodiments of the present invention, after the ethanol ultrasonic bath, it further includes: drying with nitrogen.

[0094] In certain embodiments of the present invention, the time of the ultraviolet ozone treatment is 15 min.

[0095] In certain embodiments of the present invention, the thickness of the ITO coating in the glass substrate (1) containing the ITO coating is 170 - 180 nm. In certain embodiments, the thickness of the ITO coating in the glass substrate (1) containing the ITO coating is 180 nm.

[0096] In certain embodiments of the present invention, the components of the hole - transporting mesa (2) include poly(3,4 - ethylenedioxythiophene) (PEDOT) and sodium polystyrene sulfonate (PSS). In certain embodiments of the present invention, the thickness of the hole - transporting mesa (2) is 20 - 30 nm.

[0097] In certain embodiments of the present invention, the active mesa (3) includes donor material PM6 and acceptor material Y6. In certain embodiments of the present invention, the mass ratio of the donor material PM6 to the acceptor material Y6 is 1:1.2. In certain embodiments of the present invention, the thickness of the active mesa (3) is 100 - 150 nm.

[0098] In the present invention, the electron - transporting mesa (4) includes the 1 - phenylacetylacetone chelate described above. In certain embodiments of the present invention, the thickness of the electron - transporting mesa (4) is 8 - 14 nm. In certain embodiments, the thickness of the electron - transporting mesa (4) is 14 nm, 12 nm, 10 nm or 8 nm.

[0099] In certain embodiments of the present invention, the first metal electrode (5) is an aluminum electrode. In certain embodiments of the present invention, the second metal electrode (6) is an aluminum electrode. In certain embodiments of the present invention, the third metal electrode (7) is an aluminum electrode. In certain embodiments of the present invention, the fourth metal electrode (8) is an aluminum electrode. In certain embodiments of the present invention, the fifth metal electrode (9) is an aluminum electrode. In certain embodiments of the present invention, the thicknesses of the first metal electrode (5), the second metal electrode (6), the third metal electrode (7), the fourth metal electrode (8) and the fifth metal electrode (9) are all 100 nm.

[0100] The present invention provides a method for preparing the polymer solar cell device described above, comprising the following steps:

[0101] A) Spin - coat PEDOT:PSS on the side of the glass substrate (1) containing the ITO coating that has the ITO coating. After annealing, a hole - transporting layer (2′) is obtained;

[0102] B) Under a nitrogen atmosphere, stir and dissolve the donor material PM6, the acceptor material Y6 and chloroform, mix the resulting solution with 1 - chloronaphthalene, obtain an active solution, and drop - coat it on the hole - transporting layer. After annealing, an active layer (3′) is obtained;

[0103] C) Spin-coat an ethanol solution of 1-phenylacetylacetone chelate on the active layer, and after drying, an electron transport layer (4′) is obtained;

[0104] D) Under a nitrogen atmosphere, use a scraper to scrape one end of the electron transport layer, the active layer, and the electron and hole transport layers at the edge of the device obtained in step C), exposing a part of the glass substrate with an ITO coating, to obtain a hole transport mesa (2), an active mesa (3), and an electron transport mesa (4);

[0105] E) Under a vacuum less than 5×10 -4 Pa, evaporate and deposit a metal electrode on the exposed glass substrate with an ITO coating and the electron transport mesa (4) to obtain a first metal electrode (5), a second metal electrode (6), a third metal electrode (7), a fourth metal electrode (8), and a fifth metal electrode (9).

[0106] In the present invention, PEDOT:PSS is first spin-coated on the side of the glass substrate (1) with an ITO coating that contains the ITO coating. After annealing, a hole transport layer (2′) is obtained.

[0107] The present invention has no special restrictions on the source of the PEDOT:PSS, and it can be commercially available generally. In some embodiments of the present invention, the model of the PEDOT:PSS is CLEVIOS P VP AI 4083, purchased from H.C. Stark Inc. Among them, the mass ratio of PEDOT to PSS is 1:6.

[0108] In some embodiments of the present invention, before spin-coating the PEDOT:PSS, it further includes: diluting the PEDOT:PSS with ultrapure water; the volume ratio of PEDOT:PSS to ultrapure water is 1:2.

[0109] In some embodiments of the present invention, the rotation speed of the spin-coating is 3000 rpm. In some embodiments of the present invention, the spin-coating time is 30 s.

[0110] In some embodiments of the present invention, the annealing temperature is 145-155 °C, and the annealing time is 13-18 min. In some embodiments, the annealing is carried out in an oven.

[0111] After obtaining the hole transport layer (2′), under a nitrogen atmosphere, the donor material PM6, the acceptor material Y6, and chloroform are stirred and dissolved, and the obtained solution is stirred and mixed with 1-chloronaphthalene to obtain an active liquid, which is drop-coated on the hole transport layer. After annealing, an active layer (3′) is obtained.

[0112] In certain embodiments of the present invention, the oxygen content of the nitrogen atmosphere is less than 50 ppm, and the water content of the nitrogen atmosphere is less than 50 ppm.

[0113] In certain embodiments of the present invention, the mass ratio of the donor material PM6 to the acceptor material Y6 is 1:1.2.

[0114] In certain embodiments of the present invention, the donor material PM6, the acceptor material Y6 and chloroform are stirred and dissolved, and in the resulting solution, the contents of the donor material PM6 and the acceptor material Y6 are 15-17 mg / mL. In certain embodiments, the contents of the donor material PM6 and the acceptor material Y6 are 16 mg / mL.

[0115] In certain embodiments of the present invention, the time for the stirring and dissolution is 2-3 h.

[0116] In certain embodiments of the present invention, in the active solution, the volume content of 1-chloronaphthalene is 0.5%.

[0117] In certain embodiments of the present invention, the time for the resulting solution to be stirred and mixed with 1-chloronaphthalene is 0.5 h.

[0118] In certain embodiments of the present invention, the active solution is spin-coated by a spin coater.

[0119] In certain embodiments of the present invention, the rotation speed for the spin-coating of the active solution is 3000 rpm. In certain embodiments of the present invention, the time for the spin-coating of the active solution is 30 s.

[0120] In certain embodiments of the present invention, after the active solution is spin-coated on the hole transport layer, the annealing temperature is 105-115 °C, and the annealing time is 8-12 min.

[0121] In certain embodiments of the present invention, the preparation of the active layer (3′) is carried out under a nitrogen atmosphere. In certain embodiments of the present invention, the oxygen content of the nitrogen atmosphere is less than 50 ppm, and the water content of the nitrogen atmosphere is less than 50 ppm. In certain embodiments of the present invention, the preparation of the active layer (3′) is carried out in a nitrogen glove box.

[0122] After the active layer (3′) is obtained, an ethanol solution of 1-phenylacetylacetone chelate is spin-coated on the active layer, and after drying, an electron transport layer (4′) is obtained.

[0123] In certain embodiments of the present invention, the concentration of the ethanol solution of the 1-phenylacetylacetone chelate is 0.8 to 1.2 mg / mL. The present invention places no special restrictions on the preparation method of the ethanol solution of the 1-phenylacetylacetone chelate, and any preparation method well-known to those skilled in the art can be used.

[0124] In certain embodiments of the present invention, the rotation speed of spin-coating the ethanol solution of the 1-phenylacetylacetone chelate is 2000 to 4500 rpm. In certain embodiments, the rotation speed of spin-coating the ethanol solution of the 1-phenylacetylacetone chelate is 2000 rpm, 2800 rpm, 3000 rpm, 3600 rpm, or 4200 rpm. In certain embodiments of the present invention, the spin-coating time is 30 s.

[0125] In certain embodiments of the present invention, the drying temperature is room temperature.

[0126] After obtaining the electron transport layer (4'), in a nitrogen environment, use a scraper to scrape off the electron transport layer, active layer, and electron and hole transport layer at one end of the device obtained in step C), exposing a part of the glass substrate with an ITO coating to obtain a hole transport mesa (2), an active mesa (3), and an electron transport mesa (4).

[0127] Figure 2 This is a schematic structural diagram of the device obtained in step C) provided by an embodiment of the present invention. Among them, 1 is a glass substrate with an ITO coating, 2' is a hole transport layer, 3' is an active layer, and 4' is an electron transport layer.

[0128] In certain embodiments of the present invention, the length of the edge of the exposed glass substrate with an ITO coating from the hole transport mesa (2) is 2 mm.

[0129] After obtaining the hole transport mesa (2), the active mesa (3), and the electron transport mesa (4), under a vacuum of less than 5×10 -4 Pa, evaporate a metal electrode on the exposed glass substrate with an ITO coating and the electron transport mesa (4) to obtain a first metal electrode (5), a second metal electrode (6), a third metal electrode (7), a fourth metal electrode (8), and a fifth metal electrode (9). In certain embodiments of the present invention, the vacuum of evaporation is 4.5×10 -4 Pa.

[0130] The present invention places no special restrictions on the sources of the raw materials used above, and they can be generally commercially available.

[0131] The present invention provides a 1-phenylacetylacetone chelate having the structure shown in formula (I). In formula (I), M is selected from any metal element in Group IIIA or any metal element in Group IVB. By using the 1-phenylacetylacetone chelate as a material for the electron transport layer and applying it to a polymer solar cell device, compared with other electron transport layers, the 1-phenylacetylacetone chelate can form a certain hemispherical structure on the surface of the active layer while having excellent transport ability, increasing the optical path of incident light. At the same time, after reasonably adjusting the thickness, the maximum light intensity in the device is located at the position of the active layer, enhancing the light absorption of the active layer, thereby increasing the exciton generation rate and improving the short-circuit current density and photoelectric conversion efficiency of the battery device. In addition, while improving the current of the device, this material does not change the thickness of the active layer, ensuring both the transport of carriers and the increase in the current density of the device. Furthermore, from the perspective of process preparation, the improvement of the light absorption of the active layer is achieved only through solution preparation. The polymer solar cell device does not require an optical spacer layer and an optical microcavity structure, reducing the complexity of the preparation process compared with the addition of an optical spacer layer and an optical microcavity structure, and reducing the energy consumption compared with the preparation of a thin film by magnetron sputtering. It has simple operation and remarkable effects and is suitable for large-scale commercial production.

[0132] Experimental results show that the device prepared by the present invention has a short-circuit current density greater than 25.4 mA / cm 2 under simulated sunlight illumination of 100 mW / cm 2 , and the photoelectric conversion efficiency is not less than 15.70%.

[0133] To further illustrate the present invention, the following examples will be used to describe in detail a 1-phenylacetylacetone chelate, its preparation method and application provided by the present invention, but they should not be construed as limiting the protection scope of the present invention.

[0134] All raw materials used in the following examples are commercially available.

[0135] Example 1

[0136] Prepare a ligand compound having the structure shown in formula (II):

[0137] Dissolve acetophenone (5 g, 0.042 mol) in 200 mL of ethyl acetate. Under the condition of an ice-water bath, add sodium amide (8.12 g, 0.2 mol) dropwise and react at 25°C for 1 h. Filter to obtain a white precipitate. Dissolve the white precipitate in water, add hydrochloric acid with a mass fraction of 50%, and the molar ratio of the hydrochloric acid to the white precipitate is 1:1. Obtain a precipitate by filtration, recrystallize and dry to obtain a ligand compound having the structure shown in formula (II).

[0138] Example 2

[0139] Preparation of 1-phenylacetylacetone chelate having the structure shown in formula (Ⅰ):

[0140] The ligand compound having the structure shown in formula (Ⅱ) prepared in Example 1 and HfCl4 were dissolved in an ethanol solution with a mass concentration of 99% according to a mass ratio of 6:1, stirred at 70 °C for 12 h, and the precipitate obtained by the stirring was washed with methanol to obtain 1-phenylacetylacetone chelate Hf(ACB1)4 having the structure shown in formula (Ⅰ).

[0141] The ligand compound having the structure shown in formula (Ⅱ) prepared in Example 1 and TiCl4 were dissolved in an ethanol solution with a mass concentration of 99% according to a mass ratio of 6:1, stirred at 70 °C for 12 h, and the precipitate obtained by the stirring was washed with methanol to obtain 1-phenylacetylacetone chelate Ti(ACB1)4 having the structure shown in formula (Ⅰ).

[0142] The ligand compound having the structure shown in formula (Ⅱ) prepared in Example 1 and ZrCl4 were dissolved in an ethanol solution with a mass concentration of 99% according to a mass ratio of 6:1, stirred at 70 °C for 12 h, and the precipitate obtained by the stirring was washed with methanol to obtain 1-phenylacetylacetone chelate Zr(ACB1)4 having the structure shown in formula (Ⅰ).

[0143] Example 3

[0144] Preparation of polymer solar cell device:

[0145] 1) Preparation of glass substrate (1) with ITO coating:

[0146] A layer of ITO was coated on the glass substrate by sputtering process, and successively passed through a detergent (dishwashing liquid) ultrasonic bath for 15 min (ultrasonic frequency is 40 KHz, power is 500 W), an ultrapure water ultrasonic bath for 15 min (ultrasonic frequency is 40 KHz, power is 500 W), an acetone ultrasonic bath for 15 min (ultrasonic frequency is 40 KHz, power is 500 W) and an ethanol ultrasonic bath for 15 min (ultrasonic frequency is 40 KHz, power is 500 W), dried with nitrogen, and then treated with ultraviolet ozone for 15 min to obtain an ITO layer with a thickness of 180 nm.

[0147] 2) Spin-coat the PEDOT:PSS diluted with ultrapure water (model CLEVIOS P VP AI 4083, purchased from H.C. Stark Inc, where the mass ratio of PEDOT to PSS is 1:6; the volume ratio of PEDOT:PSS to ultrapure water is 1:2) on the side of the glass substrate (1) with the ITO coating at 3000 rpm for 30 s. After annealing at 150 °C for 15 min in an oven, a hole transport layer (2′) with a thickness of 20 - 30 nm is obtained.

[0148] 3) Transfer the sample obtained in step 2) into a nitrogen glove box for subsequent operations. In the nitrogen glove box, the oxygen content is less than 50 ppm, and the water content of the nitrogen atmosphere is less than 50 ppm. Stir and dissolve the donor material PM6, the acceptor material Y6, and chloroform. The mass ratio of the donor material PM6 to the acceptor material Y6 is 1:1.2. In the resulting solution, the contents of the donor material PM6 and the acceptor material Y6 are 16 mg / mL. Stir and mix the resulting solution with 1-chloronaphthalene with a volume content of 0.5% for 0.5 h to obtain an active solution, which is drop-coated on the hole transport layer at 3000 rpm for 30 s. After annealing at 110 °C for 10 min, an active layer (3′) with a thickness of 150 nm is obtained.

[0149] 4) Spin-coat the ethanol solution of Hf(ACB1)4 prepared in Example 2 with a concentration of 1 mg / mL on the active layer at 2000 rpm for 30 s. After drying at room temperature, an electron transport layer (4′) with a thickness of 14 nm is obtained.

[0150] 5) In a nitrogen environment, use a scraper to scrape off the electron transport layer, the active layer, and the electron and hole transport layers at one end of the device obtained in step 4) to expose a part of the glass substrate with the ITO coating, obtaining a hole transport mesa (2), an active mesa (3), and an electron transport mesa (4). The length from the edge of the exposed part of the glass substrate with the ITO coating to the hole transport mesa (2) is 2 mm.

[0151] 6) Transfer the device obtained in step 5) into a vacuum coater, and pump the vacuum in the coater to 4.5×10 -4 Pa, and perform evaporation coating of the Al electrode material to obtain the first metal electrode (5), the second metal electrode (6), the third metal electrode (7), the fourth metal electrode (8), and the fifth metal electrode (9). The thicknesses of the first metal electrode (5), the second metal electrode (6), the third metal electrode (7), the fourth metal electrode (8), and the fifth metal electrode (9) are all 100 nm, thereby fabricating a polymer solar cell device.

[0152] Figure 3 This is the energy level diagram of the polymer solar cell device prepared in Example 3 of the present invention. The work function of Hf(ACB1)4 is lower than the LUMO energy level of the acceptor Y6 in the active layer, enabling electrons to be smoothly extracted from the acceptor, forming a good Ohmic contact, which is beneficial to the transport and collection of carriers.

[0153] Figure 4 This is the AFM image of the polymer solar cell device prepared in Example 3 of the present invention. It can be observed from the AFM image that a series of hemispherical structures are formed on the surface of Hf(ACB1)4. Due to the existence of this structure, the optical path of the incident light of the device is increased, improving the light absorption of the active layer, ultimately increasing the exciton generation rate, and increasing the short-circuit current density of the device.

[0154] The device prepared in this example under simulated solar illumination of 100 mW / cm 2 has an open-circuit voltage of 0.835 V, a short-circuit current density of 26.32 mA / cm 2 , a fill factor of 71.45%, and a power conversion efficiency of 15.70%. Figure 5 This is the current density-voltage curve of the polymer solar cell devices prepared in Examples 3-6 and Comparative Example 1 of the present invention under simulated solar illumination of 100 mW / cm 2 . Figure 6 This is the external quantum efficiency curve graph (EQE curve graph) of the polymer solar cell devices prepared in Examples 3-6 and Comparative Example 1 of the present invention. As can be seen from Figure 6 , with the regulation of the electron transport mesa thickness (14 nm, 12 nm, 10 nm, and 8 nm), the obtained external quantum efficiency has obvious changes, and the optimal value of 25.93% is obtained at 14 nm. By regulating the thickness of the transport layer, the light field distribution in the device is further improved, making the maximum light intensity in the device located at the position of the active layer.

[0155] Figure 7 This is the simulated distribution diagram of |E(x)| 2 of the polymer solar cell device prepared in Example 3 of the present invention under irradiation at 380 nm, 480 nm, 580 nm, and 680 nm. This figure is the simulated light field distribution diagram of the device at different wavelengths under the optimal thickness of the electron transport mesa. The thickness of the electron transport layer can be optimized according to this figure.

[0156] Figure 8 This is the simulated distribution diagram of the exciton generation rate in the BHJ of the polymer solar cell device prepared in Example 3 of the present invention. This figure is the simulated distribution diagram of the exciton generation rate in the active mesa. From Figure 8It can be clearly observed that in the high exciton generation rate region where the active mesa is around 0 - 90 nm, the incident light in the wavelength range of 400 - 800 nm is almost completely absorbed at 90 - 100 nm, and another high exciton generation rate region can be observed at 100 - 110 nm on the top of the active mesa. The light passing through the active mesa is reflected by Hf(ACB1)4, which increases the optical path of the incident light, demonstrating that this electron transport mesa improves the exciton generation rate of the device.

[0157] Example 4

[0158] Steps 1), 2), 3), 5) and 6) are the same as those in Example 3;

[0159] Step 4): Spin - coat the ethanol solution of Hf(ACB1)4 prepared in Example 2 with a concentration of 1 mg / mL on the active layer at 2800 rpm for 30 s. After drying at room temperature, an electron transport layer (4′) with a thickness of 12 nm is obtained.

[0160] The fabricated device under simulated sunlight illumination of 100 mW / cm 2 has an open - circuit voltage of 0.833 V, a short - circuit current density of 26.01 mA / cm 2 , a fill factor of 72.99%, and a power conversion efficiency of 15.81%.

[0161] Example 5

[0162] Steps 1), 2), 3), 5) and 6) are the same as those in Example 3;

[0163] Step 4): Spin - coat the ethanol solution of Hf(ACB1)4 prepared in Example 2 with a concentration of 1 mg / mL on the active layer at 3600 rpm for 30 s. After drying at room temperature, an electron transport layer (4′) with a thickness of 10 nm is obtained.

[0164] The fabricated device under simulated sunlight illumination of 100 mW / cm 2 has an open - circuit voltage of 0.835 V, a short - circuit current density of 25.83 mA / cm 2 , a fill factor of 74.42%, and a power conversion efficiency of 16.05%.

[0165] Example 6

[0166] Steps 1), 2), 3), 5) and 6) are the same as those in Example 3;

[0167] Step 4): Spin-coat the ethanol solution of Hf(ACB1)4 prepared in Example 2 with a concentration of 1 mg / mL on the active layer at 4200 rpm for 30 s. After drying at room temperature, an electron transport layer (4′) with a thickness of 8 nm is obtained.

[0168] The fabricated device under simulated sunlight of 100 mW / cm 2 has an open-circuit voltage of 0.831 V, a short-circuit current density of 25.43 mA / cm 2 , a fill factor of 75.19%, and a power conversion efficiency of 15.86%.

[0169] Example 7

[0170] Steps 1), 2), 3), 5) and 6) are the same as those in Example 3;

[0171] Step 4): Spin-coat the ethanol solution of Ti(ACB1)4 prepared in Example 2 with a concentration of 1 mg / mL on the active layer at 3000 rpm for 30 s. After drying at room temperature, an electron transport layer (4′) with a thickness of 10 nm is obtained.

[0172] The fabricated device under simulated sunlight of 100 mW / cm 2 has an open-circuit voltage of 0.830 V, a short-circuit current density of 26.11 mA / cm 2 , a fill factor of 72.14%, and a power conversion efficiency of 15.63%.

[0173] Example 8

[0174] Steps 1), 2), 3), 5) and 6) are the same as those in Example 3;

[0175] Step 4): Spin-coat the ethanol solution of Zr(ACB1)4 prepared in Example 2 with a concentration of 1 mg / mL on the active layer at 3000 rpm for 30 s. After drying at room temperature, an electron transport layer is obtained.

[0176] The fabricated device under simulated sunlight of 100 mW / cm 2 has an open-circuit voltage of 0.831 V, a short-circuit current density of 25.95 mA / cm 2 , a fill factor of 73.09%, and a power conversion efficiency of 15.74%.

[0177] Figure 9 The current density-voltage curves of the polymer solar cell devices fabricated in Examples 7-8 of the present invention under simulated sunlight of 100 mW / cm 2 are shown in the figure.Figure 10 This is the external quantum efficiency curve graph (EQE curve graph) of the polymer solar cell device prepared in Examples 7 - 8 of the present invention.

[0178] Comparative Example 1

[0179] Steps 1), 2), 3), 5) and 6) are the same as those in Example 3;

[0180] Step 4): Spin - coat a methanol solution of PFN - Br (poly[(9,9 - bis(3'-(N,N - dimethyl)-N - ethylaminopropyl - propyl)-2,7 - fluorene)-2,2,7-(9,9 - dioctylfluorene)] dibromoimide) with a concentration of 1 mg / mL on the active layer. Spin - coat at 4400 rpm for 30 s, and after drying at room temperature, an electron transport layer (4') with a thickness of 10 nm is obtained.

[0181] The fabricated device under simulated sunlight illumination of 100 mW / cm 2 has an open - circuit voltage of 0.833 V, a short - circuit current density of 24.76 mA / cm 2 , a fill factor of 72.26%, and a photoelectric conversion efficiency of 14.88%.

[0182] The experimental results show that the device prepared by the present invention under simulated sunlight illumination of 100 mW / cm 2 has a short - circuit current density greater than 25.4 mA / cm 2 , and a photoelectric conversion efficiency higher than 15.60%.

[0183] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A polymer solar cell device, comprising: A glass substrate (1) with an ITO coating; A hole transport mesa (2) is compounded on one side of the glass substrate with the ITO coating; A first metal electrode (5) is also provided on one side of the glass substrate with the ITO coating; An active mesa (3) is compounded on the hole transport mesa; An electron transport mesa (4) is compounded on the active mesa; A second metal electrode (6), a third metal electrode (7), a fourth metal electrode (8), and a fifth metal electrode (9) are provided on the electron transport mesa; The electron transport mesa (4) includes a 1-phenylacetylacetone chelate, and the 1-phenylacetylacetone chelate has the structure shown in formula (Ⅰ); （Ⅰ）； （Ⅱ）； In formula (Ⅰ), M is selected from Ti, Zr, or Hf; The preparation method of the 1-phenylacetylacetone chelate consists of the following steps: Dissolve a ligand compound with the structure shown in formula (Ⅱ) and a chloride of M in an ethanol solution, stir at 65 - 75 °C, and wash the precipitate obtained from the stirring with methanol to obtain a 1-phenylacetylacetone chelate with the structure shown in formula (Ⅰ).

2. The polymer solar cell device according to claim 1, wherein The ligand compound with the structure shown in formula (Ⅱ) is prepared according to the following method: a) Mix acetophenone and ethyl acetate to obtain a first mixed solution; b) Under the condition of an ice-water bath, dropwise add sodium amide to the first mixed solution and react to obtain a white precipitate; c) Mix the white precipitate, water, and hydrochloric acid solution, filter, and the obtained precipitate is recrystallized and dried to obtain a ligand compound with the structure shown in formula (Ⅱ).

3. The polymer solar cell device according to claim 1, wherein The thickness of the ITO coating in the glass substrate (1) with the ITO coating is 170 - 180 nm; The thickness of the hole transport mesa (2) is 20 - 30 nm; The thickness of the active mesa (3) is 100 - 150 nm; The thickness of the electron transport mesa (4) is 8 - 14 nm.

4. The preparation method of the polymer solar cell device according to claim 1, comprising the following steps: A) Spin-coat PEDOT:PSS on one side of the glass substrate (1) with the ITO coating, and after annealing, obtain a hole transport layer (2'); B) Under a nitrogen atmosphere, stir and dissolve the donor material PM6, the acceptor material Y6, and chloroform, mix the obtained solution with 1-chloronaphthalene, obtain an active solution, and drop-coat it on the hole transport layer, and after annealing, obtain an active layer (3'); C) Spin-coat an ethanol solution of the 1-phenylacetylacetone chelate on the active layer, and after drying, obtain an electron transport layer (4'); D) Under a nitrogen environment, scrape off the electron transport layer, the active layer, and the electron and hole transport layers at one end of the device obtained in step C) to expose a part of the glass substrate with the ITO coating, and obtain a hole transport mesa (2), an active mesa (3), and an electron transport mesa (4); E) At a vacuum degree less than 5×10 -4 Pa, a metal electrode is vapor-deposited on the exposed glass substrate with an ITO coating and the electron transport mesa (4) to obtain a first metal electrode (5), a second metal electrode (6), a third metal electrode (7), a fourth metal electrode (8) and a fifth metal electrode (9).

5. The preparation method according to claim 4, characterized in that, The glass substrate (1) with the ITO coating is prepared according to the following method: Cover a layer of ITO on a glass substrate by sputtering process, and successively pass through ultrasonic baths with detergent, ultrapure water, acetone and ethanol, and then perform ultraviolet ozone treatment to obtain the ITO layer; In step A), the annealing temperature is 145-155 °C, and the annealing time is 13-18 min.

6. The preparation method according to claim 4, wherein In step B), the mass ratio of the donor material PM6 to the acceptor material Y6 is 1:1.2; For the obtained solution, the contents of the donor material PM6 and the acceptor material Y6 are 15-17 mg / mL; The annealing temperature is 105-115 °C, and the annealing time is 8-12 min.

7. The preparation method according to claim 4, characterized in that, In step C), the concentration of the ethanol solution of 1-phenylacetylacetone chelate is 0.8-1.2 mg / mL; The rotation speed of the spin coating is 2000-4500 rpm, and the spin coating time is 30 s.

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