Perovskite solar cells with rare earth ion modified hole transport layer and preparation thereof

Abstract

The application discloses a perovskite solar cell with a rare earth ion modified hole transport layer, which comprises, from bottom to top, an ITO conductive glass layer, a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) hole transport layer, a CeCl3 hole modification layer, a MAPbI 2.91 Br 0.09 a perovskite layer (PVSK), a 9-octadecenyl-iodoamine (OAmI) perovskite transport layer, a [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) electron transport layer, a 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) hole blocking layer and a metal Ag electrode layer. The scheme modifies the hole transport layer by using a rare earth ion, thereby regulating the growth of the perovskite film, and has the advantages of improved film quality, enhanced crystallinity, inhibited carrier recombination, shortened hole extraction time and high stability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solar cells, and particularly relates to a perovskite solar cell with a hole transport layer modified by rare earth ions and preparation thereof. BACKGROUND

[0002] With the rapid economic development, global energy consumption is increasing dramatically, and the depletion of fossil fuels forces people to develop and research sustainable and renewable energy. Among them, solar cells using photovoltaic effect to convert light energy into electrical energy have broad application prospects, which are expected to fundamentally solve the energy demand of human society's sustainable development and will not have a negative impact on the global climate, and have received widespread attention from the international community.

[0003] Today, solar cells have undergone three updates, and organic-inorganic hybrid perovskite solar cells have made rapid progress in just thirteen years, with a photoelectric conversion efficiency (PCE) of 25.7%. In addition, compared with the complex and precise preparation process of single crystal silicon solar cells, the preparation process of perovskite solar cells is simple and low in cost, which has great potential to surpass commercial silicon solar cells. However, organic-inorganic hybrid perovskite has the characteristics of easy water absorption and oxidation, which leads to poor stability, and the efficiency will decrease significantly when exposed to air and strong light radiation, thus limiting its commercial application. In addition, the incorporation of rare earth is described in many literatures, but the metal salt is usually added to the perovskite precursor solution, and the doping effect is usually limited by the inherent defect compensation in the perovskite, and even new defects are introduced, and it is difficult to control the growth of the perovskite lattice.

[0004] In order to solve the above problems, the application provides a perovskite solar cell with a hole transport layer modified by rare earth ions and preparation thereof. SUMMARY

[0005] In order to achieve the above technical effects, the application is implemented by the following technical scheme: a perovskite solar cell with a hole transport layer modified by rare earth ions, characterized in that, from bottom to top, it comprises an ITO conductive glass layer, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) as a hole transport layer, CeCl3 as a hole modification layer, MAPbI 2.91 Br 0.09 perovskite layer (PVSK), 9-octadecenyl iodide (OAmI) as a perovskite transport layer, [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM) as an electron transport layer, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) as a hole blocking layer, and a metal Ag electrode layer.

[0006] Preferably, the preparation procedure of the hole transport layer and the hole modification layer is as follows:

[0007] S1, hole modification layer: dissolve different mass fractions of CeCl3 in anhydrous ethanol to obtain a CeCl3 solution;

[0008] S2, hole transport layer: dissolve PTAA in toluene solution to obtain a PTAA solution.

[0009] Preferably, the specific steps in S1 are as follows:

[0010] Dissolve 0.2 mg of CeCl3 in 1 ml of anhydrous ethanol to obtain a 0.2 mg / ml CeCl3 stock solution;

[0011] Take 500 μl, 100 μl, 50 μl, 10 μl and 0 μl from the CeCl3 stock solution, respectively, and then add 500 μl, 900 μl, 950 μl, 990 μl and 1 ml of anhydrous ethanol, respectively, to obtain a CeCl3 solution of 0-0.1 mg / ml;

[0012] The different mass fractions of CeCl3 in S1 are 0, 0.1 wt%, 0.5 wt%, 1 wt% and 5 wt%, respectively;

[0013] The specific steps in S2 are as follows: dissolve 2 mg of PTAA in 1 ml of toluene solution to obtain a 2 mg / ml PTAA solution.

[0014] Preferably, the preparation procedure of the perovskite MAPbI 2.91 Br 0.09 is as follows:

[0015] Step 1: dissolve PbI2, MAI and MABr in a molar ratio of 1:0.91:0.09 in ACN solution, then add an equal amount of methylamine solution to form a 1.2 M MAPbI 2.91 Br 0.09 solution;

[0016] Step 2: stir for 3 h on a magnetic stirrer, then filter the solution into a sample bottle to produce a perovskite precursor solution.

[0017] Preferably, the specific operation in step 1 is as follows: dissolve 553.20 mg of PbI2, 185.09 mg of MAI and 4.03 mg of MABr in 800 ml of ACN solution, then add 800 ml of methylamine solution to form a MAPbI 2.91 Br 0.09 solution.

[0018] Another object of the present application is to provide a preparation method of a perovskite solar cell with a rare earth ion modified hole transport layer, characterized in that it comprises the following steps:

[0019] Step 1: sequentially clean the ITO glass substrate with detergent, isopropyl alcohol solution, anhydrous ethanol and deionized water, dry it and then clean it with a UV-ozone cleaner for 30-60 min;

[0020] Step 2: spin-coat a hole transport layer PTAA on the cleaned ITO glass substrate, and then anneal it at 100-150 DEG C for 10-15 min;

[0021] Step 3: dynamically spin-coat a CeCl3 solution on the hole transport layer PTAA at 2000-4000 rpm, and then anneal it at 100-150 DEG C for 10-15 min;

[0022] Step 4: dynamically spin-coat a perovskite precursor solution on the hole modification layer CeCl3 at 3000-6000 rpm, and then anneal it at 100-150 DEG C for 10-15 min;

[0023] Step 5: dynamically spin-coat a MAPbI 2.91 Br 0.09 on the perovskite layer at 3000-6000 rpm

[0024] OAmI solution;

[0025] Step 6: dynamically spin-coat a PCBM solution on the perovskite transport layer at 1000-2000 rpm;

[0026] Step 7: dynamically spin-coat a BCP solution on the electron transport layer at 3000-6000 rpm;

[0027] Step 8: evaporate a metal electrode Ag on the hole blocking layer BCP in a vacuum coating machine, with a thickness of 100-120 nm.

[0028] The present application has the following advantages:

[0029] 1) In the present application, the rare earth ion Ce 3+ is introduced into the hole transport layer, and is induced to migrate to the perovskite lattice and surface by annealing, which promotes the growth of perovskite crystals, increases the grain size, passivates the bulk defects and surface defects of the perovskite layer, and improves the film quality;

[0030] 2) In the present application, the rare earth ion Ce 3+The existence of the rare earth ions Ce

[0031] 3) In the present application, the rare earth ions Ce 3+ In the doping of the perovskite light-absorbing layer, the stability of the solar cell is enhanced, the dark current of the perovskite solar cell is reduced, and the open-circuit voltage (VOC) of the perovskite solar cell is improved, thereby improving the photoelectric conversion efficiency (PCE) of the perovskite solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0033] Figure 1 The photoelectric conversion efficiency (PCE), current density (JSC), open-circuit voltage (VOC) and fill factor (FF) statistical graphs of Example 1, Example 2, Example 3, Example 4 and Example 5;

[0034] Figure 2 The J-V curve graphs of Example 1, Example 2, Example 3, Example 4 and Example 5;

[0035] Figure 3 The EDS graphs of Example 1 and Example 3;

[0036] Figure 4 The SEM graphs of Example 1 and Example 3;

[0037] Figure 5 The absorption and trPL spectrum graphs of Example 1 and Example 3;

[0038] Figure 6 The energy level graphs of Example 1 and Example 3;

[0039] Figure 7 The J-V curve graphs of Example 1 and Example 3 in dark conditions;

[0040] Figure 8 The photoelectric conversion efficiency (PCE) graphs of Example 1 and Example 3 in air for 500h. DETAILED DESCRIPTION

[0041] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of the present application.

[0042] Embodiment 1

[0043] A perovskite solar cell with a rare earth ion modified hole transport layer, the device structure is from bottom to top:

[0044] ITO / PTAA / MAPbI 2.91 Br 0.09 / OAmI / PCBM / BCP / Ag

[0045] The preparation method is as follows:

[0046] S1: sequentially clean the ITO glass substrate with detergent, isopropanol solution, anhydrous ethanol and deionized water, and dry it, and then clean it with an ultraviolet ozone cleaning machine for 40 min;

[0047] S2: spin-coat a hole transport layer PTAA on the cleaned ITO glass substrate, and then anneal it at 100 degrees Celsius for 10 min;

[0048] S3: dynamically spin-coat a CeCl3 solution on the hole transport layer PTAA at 3000 rpm, and then anneal it at 100 degrees Celsius for 10 min;

[0049] S4: dynamically spin-coat a perovskite precursor solution on the hole modification layer CeCl3 at 6000 rpm, and then anneal it at 100 degrees Celsius for 10 min;

[0050] S5: dynamically spin-coat an OAmI solution on the perovskite layer MAPbI 2.91 Br 0.09 at 6000 rpm;

[0051] S6: dynamically spin-coat a PCBM solution on the perovskite transport layer at 1500 rpm;

[0052] S7: dynamically spin-coat a BCP solution on the electron transport layer at 6000 rpm;

[0053] S8: evaporate a metal electrode Ag on the hole blocking layer BCP in a vacuum coating machine, and the thickness is 120 nm.

[0054] Embodiment 2

[0055] A perovskite solar cell with a rare earth ion modified hole transport layer, the device structure is from bottom to top:

[0056] ITO / PTAA:Ce 3+ (0.1wt%) / MAPbI 2.91 Br 0.09 / OAmI / PCBM / BCP / Ag

[0057] The preparation method is as follows:

[0058] S1: sequentially clean the ITO glass substrate with dishwashing liquid, isopropanol solution, anhydrous ethanol and deionized water, dry and clean with a UV ozone cleaning machine for 40 min;

[0059] S2: spin-coat the hole transport layer PTAA on the cleaned ITO glass substrate, and then anneal at 100 degrees Celsius for 10 min;

[0060] S3: dynamically spin-coat the CeCl3(0.1wt%) solution on the hole transport layer PTAA at 3000 rpm, and then anneal at 100 degrees Celsius for 10 min;

[0061] S4: dynamically spin-coat the perovskite precursor solution on the hole modification layer CeCl3 at 6000 rpm, and then anneal at 100 degrees Celsius for 10 min;

[0062] S5: dynamically spin-coat the OAmI solution on the perovskite layer MAPbI 2.91 Br 0.09 at 6000 rpm;

[0063] S6: dynamically spin-coat the PCBM solution on the perovskite transport layer at 1500 rpm;

[0064] S7: dynamically spin-coat the BCP solution on the electron transport layer at 6000 rpm;

[0065] S8: evaporate the metal electrode Ag on the hole blocking layer BCP in a vacuum coating machine, with a thickness of 120 nm.

[0066] Example 3

[0067] A perovskite solar cell with a rare earth ion modified hole transport layer, the device structure is from bottom to top:

[0068] ITO / PTAA:Ce 3+ (0.5wt%) / MAPbI 2.91 Br 0.09 / OAmI / PCBM / BCP / Ag

[0069] The preparation method is as follows:

[0070] S1: The ITO glass substrate was sequentially cleaned with dishwashing liquid, isopropanol solution, anhydrous ethanol and deionized water, and then dried and cleaned with a UV ozone cleaning machine for 40 min;

[0071] S2: The hole transport layer PTAA was spin-coated on the cleaned ITO glass substrate, and then annealed at 100°C for 10 min;

[0072] S3: The CeCl3(0.5wt%) solution was dynamically spin-coated on the hole transport layer PTAA at 3000 rpm, and then annealed at 100°C for 10 min;

[0073] S4: The perovskite precursor solution was dynamically spin-coated on the hole modification layer CeCl3at 6000 rpm, and then annealed at 100°C for 10 min;

[0074] S5: The OAmI solution was dynamically spin-coated on the perovskite layer MAPbI 2.91 Br 0.09 at 6000 rpm;

[0075] S6: The PCBM solution was dynamically spin-coated on the perovskite transport layer at 1500 rpm;

[0076] S7: The BCP solution was dynamically spin-coated on the electron transport layer at 6000 rpm;

[0077] S8: The metal electrode Ag was evaporated on the hole blocking layer BCP in a vacuum coating machine, with a thickness of 120 nm.

[0078] Example 4

[0079] A perovskite solar cell with a rare earth ion modified hole transport layer, the device structure is from bottom to top:

[0080] ITO / PTAA:Ce 3+ (1wt%) / MAPbI 2.91 Br 0.09 / OAmI / PCBM / BCP / Ag

[0081] The preparation method is as follows:

[0082] S1: The ITO glass substrate was sequentially cleaned with dishwashing liquid, isopropanol solution, anhydrous ethanol and deionized water, and then dried and cleaned with a UV ozone cleaning machine for 40 min;

[0083] S2: The hole transport layer PTAA was spin-coated on the cleaned ITO glass substrate, and then annealed at 100°C for 10 min;

[0084] S3: spin-coat CeCl3(1 wt%) solution on the hole transport layer PTAA at 3000 rpm, followed by annealing at 100 degree Celsius for 10 min;

[0085] S4: spin-coat perovskite precursor solution on the hole modification layer CeCl3at 6000 rpm, followed by annealing at 100 degree Celsius for 10 min;

[0086] S5: spin-coat OAmI solution on the perovskite layer MAPbI 2.91 Br 0.09 at 6000 rpm;

[0087] S6: spin-coat PCBM solution on the perovskite transport layer at 1500 rpm;

[0088] Page 8 of 10

[0089] S7: spin-coat BCP solution on the electron transport layer at 6000 rpm;

[0090] S8: evaporate metal electrode Ag on the hole blocking layer BCP in a vacuum coating machine, thickness is 120 nm.

[0091] Example 5

[0092] A perovskite solar cell with a rare earth ion modified hole transport layer, the device structure is from bottom to top:

[0093] ITO / PTAA:Ce 3+ (5 wt%) / MAPbI 2.91 Br 0.09 / OAmI / PCBM / BCP / Ag

[0094] The preparation method is as follows:

[0095] S1: clean the ITO glass substrate with washing-up liquid, isopropyl alcohol solution, anhydrous ethanol and deionized water in turn, dry after baking, clean with ultraviolet ozone cleaning machine for 40 min;

[0096] S2: spin-coat hole transport layer PTAA on the cleaned ITO glass substrate, followed by annealing at 100 degree Celsius for 10 min;

[0097] S3: spin-coat CeCl3(5 wt%) solution on the hole transport layer PTAA at 3000 rpm, followed by annealing at 100 degree Celsius for 10 min;

[0098] S4: spin-coat perovskite precursor solution on the hole modification layer CeCl3at 6000 rpm, followed by annealing at 100 degree Celsius for 10 min;

[0099] S5: Dynamic spin-coating OAmI solution on perovskite layer MAPbI 2.91 Br 0.09 Dynamic spin-coating OAmI solution on perovskite layer MAPbI at 6000 rpm;

[0100] S6: Dynamic spin-coating PCBM solution on perovskite transport layer at 1500 rpm;

[0101] S7: Dynamic spin-coating BCP solution on electron transport layer at 6000 rpm;

[0102] S8: Evaporating metal electrode Ag on hole blocking layer BCP in vacuum coating machine, thickness is 120 nm.

[0103] From the attached Figure 1 and 2 It can be seen that by introducing Ce 3+ , the photoelectric conversion efficiency (PCE), current density (JSC), open circuit voltage (VOC) and fill factor (FF) of the perovskite device are obviously improved, and when the doping amount of Ce 3+ is 0.5wt%, the photoelectric conversion efficiency (PCE) can be increased by more than 27%.

[0104] From the attached Figure 3 , it can be seen that Ce 3+ exists on the perovskite lattice and surface. 3+ This shows that Ce 3+ is successfully induced to migrate to the perovskite lattice and surface by annealing, and part of Ce 2+ replaces Pb 2.91 .

[0105] From the attached Figure 4 , it can be seen that compared with the original MAPbI 2.91 Br 0.09 film, the Ce 3+ doped perovskite film has larger grain size, better crystallinity and fewer surface defects.

[0106] From the attached Figure 5 , it can be seen that in the absorption spectrum, compared with the original MAPbI 2.91 Br 0.09 film, the absorption range of the Ce 3+ doped perovskite device does not change, so the band gap does not change. At the same time, it can also be seen from the trPL graph that the carrier lifetime of the Ce 3+ doped perovskite device is obviously reduced, which shows that the existence of Ce 3+ suppresses the recombination of carriers at the interface, which is beneficial to the extraction of holes and electrons.

[0107] From the attached Figure 6 , it can be seen that Ce 3+The Fermi level of the doped perovskite device is higher, and Ce 3+ The LUMO of the doped perovskite device is closer to the LUMO of PCBM, Ag, which improves the electron mobility and in turn improves the current density (JSC) of the perovskite solar cell.

[0108] By attaching Figure 7 It can be seen that the Ce 3+ The dark current of the doped perovskite device is lower, which in turn improves the open-circuit voltage (VOC) of the perovskite solar cell.

[0109] By attaching Figure 8 It can be seen that the original perovskite device has a 39% decrease in photoelectric conversion efficiency (PCE) after 500h, while the Ce 3+ The doped perovskite device still maintains more than 92% after 500h, which shows that the doping of Ce 3+ effectively improves the stability of the perovskite solar cell.

Claims

1. A perovskite solar cell with a rare earth ion-modified hole transport layer, characterized in that, From bottom to top in turn includes ITO conductive glass layer, poly [bis (4-phenyl) (2, 4, 6-trimethylphenyl) amine] (PTAA) hole transport layer, CeCl3 hole modification layer, MAPbI 2.91 Br 0.09 Perovskite layer (PVSK), 9-octadecenyl iodide amine (OAmI) perovskite transport layer, [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM) electron transport layer, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) hole blocking layer and metal Ag electrode layer.

2. The perovskite solar cell with a rare earth ion modified hole transport layer according to claim 1, characterized in that, The preparation procedure of the hole transport layer and the hole modification layer is as follows: S1, hole modification layer: dissolve different mass fractions of CeCl3 in anhydrous ethanol to obtain a CeCl3 solution; S2, hole transport layer: dissolve PTAA in toluene solution to obtain a PTAA solution.

3. The perovskite solar cell with a hole transport layer modified by rare earth ions according to claim 2, characterized in that, The specific steps in S1 are as follows: Dissolve 0.2 mg of CeCl3 in 1 ml of anhydrous ethanol to obtain a 0.2 mg / ml CeCl3 stock solution; Take 500 μl, 100 μl, 50 μl, 10 μl and 0 μl from the CeCl3 stock solution, and then add 500 μl, 900 μl, 950 μl, 990 μl and 1 ml of anhydrous ethanol respectively, thereby obtaining a CeCl3 solution with a mass fraction of 0-0.1 mg / ml; The different mass fractions of CeCl3 in S1 are 0, 0.1 wt%, 0.5 wt%, 1 wt% and 5 wt% respectively; The specific steps in S2 are as follows: dissolve 2 mg of PTAA in 1 ml of toluene solution to obtain a 2 mg / ml PTAA solution. 4.The perovskite solar cell with a rare earth ion modified hole transport layer according to claim 1, wherein The perovskite MAPbI 2.91 Br 0.09 is prepared as follows: Step 1 : Dissolve PbI2, MAI and MABr in a molar ratio of 1 :0.91 :0.09 in ACN solution, then add an equal amount of methylamine solution to form 1.2M MAPbI 2.91 Br 0.09 solution; Step 2: stir for 3 h on a magnetic stirrer, and then filter the solution into a sample bottle to produce a perovskite precursor solution.

5. The perovskite solar cell with a rare earth ion modified hole transport layer according to claim 4, characterized in that, The specific operation in step 1 is: 553.20 mg of PbI2, 185.09 mg of MAI and 4.03 mg of MABr are dissolved in 800 ml of ACN solution, and then 800 ml of methylamine solution is added to form MAPbI 2.91 Br 0.09 solution.

6. A method for preparing a perovskite solar cell with a rare earth ion-modified hole transport layer, characterized in that, The steps include: Step 1: clean the ITO glass substrate with washing-up liquid, isopropyl alcohol solution, anhydrous ethanol and deionized water in sequence, dry it, and then clean it with a UV-ozone cleaner for 30-60 min; Step 2: spin-coat the hole transport layer PTAA on the cleaned ITO glass substrate, and then anneal it at 100-150°C for 10-15 min; Step 3: dynamically spin-coat the CeCl3 solution on the hole transport layer PTAA at 2000-4000 rpm, and then anneal it at 100-150°C for 10-15 min; Step 4: dynamically spin-coat the perovskite precursor solution on the hole modification layer CeCl3 at 3000-6000 rpm, and then anneal it at 100-150°C for 10-15 min; Step 5: dynamically spin-coat the OAmI solution on the perovskite layer MAPbI2.91Br0.09 at 3000-6000 rpm; Step 6: dynamically spin-coat the PCBM solution on the perovskite transport layer at 1000-2000 rpm; Step 7: dynamically spin-coat the BCP solution on the electron transport layer at 3000-6000 rpm; Step 8: evaporate a metal electrode Ag on the hole blocking layer BCP in a vacuum coating machine, and the thickness is 100-120 nm.

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