CN115915787A - Perovskite solar cells with hole transport layer modified by rare earth ions and its preparation - Google Patents

Abstract

The invention discloses a perovskite solar cell with a hole transport layer modified by rare earth ions, which sequentially comprises an ITO (indium tin oxide) conductive glass layer and rare earth ions Ce from bottom to top ³⁺ Modified poly [ bis (4-phenyl) (2, 4, 6-trimethylphenyl) amine](PTAA) as hole transport layer, MAPbI _3‑x Br _x As Perovskites (PVSK), 9-octadecenylsAmine iodide (OAmI) as a perovskite transport layer, [6,6]-phenyl-C61-butyric acid isopropyl ester (PCBM) as electron transport layer, 2, 9-dimethyl-4, 7-biphenyl-1, 10-phenanthroline (BCP) as hole blocking layer and metal Ag electrode layer. According to the scheme, the hole transport layer is modified by rare earth ions, so that the growth of the perovskite thin film is regulated and controlled, and the perovskite thin film has the advantages of improving the quality of the thin film, enhancing the crystallinity, inhibiting the recombination of carriers, shortening the extraction time of holes, being high in stability and the like.

Description

Perovskite solar cells with hole transport layer modified by rare earth ions and its preparation

technical field

The invention belongs to the technical field of solar cells, and in particular relates to a perovskite solar cell with a hole transport layer modified by rare earth ions and its preparation.

Background technique

With the rapid economic development, global energy consumption is increasing rapidly, and the depletion of fossil fuels forces people to develop and research sustainable and renewable energy. Among them, solar cells that use the photovoltaic effect to convert light energy into electrical energy have broad application prospects and are expected to fundamentally solve the energy needs of the sustainable development of human society without negatively affecting the global climate. They have been widely recognized by the international community. focus on.

Today, solar cells have undergone three update iterations, among which organic-inorganic hybrid perovskite solar cells have developed by leaps and bounds in just thirteen years, and their photoelectric conversion efficiency (PCE) has reached 25.7%. In addition, compared with the complex and precise preparation process of monocrystalline silicon solar cells, the preparation process of perovskite solar cells is simple and low-cost, and has great potential to surpass commercial silicon solar cells. However, organic-inorganic hybrid perovskites are prone to water absorption and oxidation, resulting in poor stability and significantly reduced efficiency when exposed to air and strong light radiation, thus limiting their commercial applications. In addition, the doping of rare earths has been described in many literatures, but it is usually the addition of metal salts to the perovskite precursor solution. The effect of doping is usually limited by the compensation of inherent defects in the perovskite, and even introduces new defects, and it is difficult to control the growth of the perovskite lattice.

In order to solve the above problems, the present invention proposes a perovskite solar cell with a hole transport layer modified by rare earth ions and its preparation.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention provides a perovskite solar cell with a hole transport layer modified by rare earth ions and its preparation. The hole transport layer is modified by rare earth ions to regulate the growth of the perovskite film, which has improved The advantages of thin film quality, enhanced crystallinity, suppression of carrier recombination, shortened hole extraction time, and high stability.

In order to achieve the above-mentioned technical purpose, the present invention is achieved through the following technical solutions: a perovskite solar cell with a hole transport layer modified by rare earth ions, which is characterized in that it includes an ITO conductive glass layer from bottom to top, rare earth ions Ce ³⁺ modified poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine](PTAA) as hole transport layer, MAPbI _2.91 Br _0.09 as perovskite (PVSK), 9 -octadecenyl amine iodide (OAmI) as the perovskite transport layer, [6,6]-phenyl-C61-butyric acid isomethyl (PCBM) as the electron transport layer, 2,9-dimethyl- 4,7-biphenyl-1,10-phenanthroline (BCP) was used as a hole blocking layer and a metal Ag electrode layer.

Preferably, the preparation process of the hole transport layer and the hole modification layer is as follows:

S1: Dissolving CeCl ₃ with different mass fractions in absolute ethanol to obtain a CeCl ₃ solution;

S2: dissolving PTAA in toluene solution to obtain PTAA solution.

Preferably, the specific steps in the S1 are:

Dissolve 0.2 mg of CeCl in 1 ml of absolute ethanol to obtain 0.2 mg _/ ml of CeCl ₃ mother solution;

Take 500 μl, 100 μl, 50 μl, 10 μl and 0 μl respectively from the CeCl ₃ mother solution, and then add 500 μl, 900 μl, 950 μl, 990 μl and 1 ml of absolute ethanol respectively to obtain a 0-0.1 mg/ml CeCl ₃ solution;

The different mass fractions of _CeCl described in S1 are 0, 0.1wt%, 0.5wt%, 1wt% and 5wt%, respectively;

The specific steps in S2 are: dissolving 2 mg of PTAA in 1 ml of toluene solution to obtain a 2 mg/ml PTAA solution.

Preferably, the preparation process of the perovskite MAPbI _2.91 Br _0.09 is as follows:

Step 1: Dissolve PbI ₂ , MAI and MABr with a molar ratio of 1:0.91:0.09 in ACN solution, and then add an equal amount of methylamine solution to form a 1.2M MAPbI _2.91 Br _0.09 solution;

Step 2: After stirring for 3 h on a magnetic stirrer, the solution was filtered into a sample vial, resulting in a perovskite precursor.

Preferably, the specific operation in step 1 is: dissolving 553.20 mg of PbI ₂ , 185.09 mg of MAI and 4.03 mg of MABr in 800 ml of ACN solution, and then adding 800 ml of methylamine solution to form MAPbI _3-x Br _x solution.

Another object of the present invention is to propose a method for preparing a perovskite solar cell with a rare earth ion modified hole transport layer, which is characterized in that it includes the following steps:

Step1: Use detergent, isopropanol solution, absolute ethanol and deionized water to clean the ITO glass substrate in sequence, and after drying, clean it with a UV-ozone cleaner for 30-60 minutes;

Step2: Spin-coat the hole transport layer PTAA on the cleaned ITO glass substrate, and then anneal at 100-150 degrees Celsius for 10-15 minutes;

Step3: Dynamically spin-coat CeCl ₃ solution at 2000-4000rpm on the hole transport layer PTAA, and then anneal at 100-150 degrees Celsius for 10-15min;

Step4: Spin-coat the perovskite precursor solution dynamically at 3000-6000rpm on the hole modifying layer _CeCl3 , and then anneal at 100-150 degrees Celsius for 10-15min;

Step5: Spin-coat the OAmI solution dynamically at 3000-6000rpm on the perovskite layer MAPbI _2.91 Br _0.09 ;

Step6: Dynamically spin-coat PCBM solution at 1000-2000rpm on the perovskite transport layer;

Step7: Spin BCP solution dynamically at 3000-6000rpm on the electron transport layer;

Step8: Evaporate metal electrode Ag on the hole blocking layer BCP in a vacuum coating machine, with a thickness of 100-120nm.

The beneficial effects of the present invention are:

1) In the present invention, the rare earth ion Ce ³⁺ is introduced into the hole transport layer, and it is induced to migrate to the perovskite lattice and surface by annealing, which promotes the growth of the perovskite crystal and increases the grain size. Size, passivation of bulk defects and surface defects of the perovskite layer, improving the quality of the film;

2) In the present invention, the presence of rare earth ions Ce ³⁺ inhibits the recombination of carriers at the interface, shortens the extraction time of holes, enhances the mobility of electrons, and then improves the current density of perovskite solar cells ( J _SC );

3) In the present invention, the doping of rare earth ions Ce in the perovskite light-absorbing layer enhances the stability of ^the solar cell, reduces the dark current of the perovskite solar cell, and then improves the performance of the perovskite solar cell. The open circuit voltage (V _OC ) and thus the photoelectric conversion efficiency (PCE) of perovskite solar cells are improved.

Description of drawings

Fig. 1 is the photoelectric conversion efficiency (PCE), current density (J _SC ), open circuit voltage (V _OC ) and fill factor (FF) statistics of embodiment 1, embodiment 2, embodiment 3, embodiment 4 and embodiment 5 picture;

Fig. 2 is the J-V curve diagram of embodiment 1, embodiment 2, embodiment 3, embodiment 4 and embodiment 5;

Fig. 3 is the EDS figure of embodiment 1 and embodiment 3

Fig. 4 is the SEM figure of embodiment 1 and embodiment 3;

Fig. 5 is the absorption and trPL spectrogram of embodiment 1 and embodiment 3;

Fig. 6 is the energy level figure of embodiment 1 and embodiment 3;

Fig. 7 is the J-V curve figure of embodiment 1 and embodiment 3 under dark conditions;

Fig. 8 is the photoelectric conversion efficiency (PCE) graph of embodiment 1 and embodiment 3 in air for 500h.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Example 1

A perovskite solar cell with a hole transport layer modified by rare earth ions, the device structure from bottom to top is:

ITO/PTAA/MAPbI _2.91 Br _0.09 /OAmI/PCBM/BCP/Ag

The preparation method is as follows:

S1: Clean the ITO glass substrate with detergent, isopropanol solution, absolute ethanol and deionized water in sequence, and clean it with a UV-ozone cleaner for 40 minutes after drying;

S2: Spin-coat the hole transport layer PTAA on the cleaned ITO glass substrate, and then anneal at 100 degrees Celsius for 10 minutes;

S3: Dynamically spin-coat CeCl ₃ solution at 3000 rpm on the hole transport layer PTAA, followed by annealing at 100 degrees Celsius for 10 min;

S4: Spin-coat the perovskite precursor solution dynamically at 6000 rpm on the hole modifying layer CeCl ₃ , and then anneal at 100 degrees Celsius for 10 minutes;

S5: Spin-coat OAmI solution dynamically at 6000rpm on the perovskite layer MAPbI _2.91 Br _0.09 ;

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

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

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

Example 2

A perovskite solar cell with a hole transport layer modified by rare earth ions, the device structure from bottom to top is:

ITO/PTAA: Ce ³⁺ (0.1wt%)/MAPbI _2.91 Br _0.09 /OAmI/PCBM/BCP/Ag

The preparation method is as follows:

S1: Clean the ITO glass substrate with detergent, isopropanol solution, absolute ethanol and deionized water in sequence, and clean it with a UV-ozone cleaner for 40 minutes after drying;

S2: Spin-coat the hole transport layer PTAA on the cleaned ITO glass substrate, and then anneal at 100 degrees Celsius for 10 minutes;

S3: dynamically spin-coat CeCl ₃ (0.1wt%) solution on the hole transport layer PTAA at 3000rpm, and then anneal at 100 degrees Celsius for 10min;

S4: Spin-coat the perovskite precursor solution dynamically at 6000 rpm on the hole modifying layer CeCl ₃ , and then anneal at 100 degrees Celsius for 10 minutes;

S5: Spin-coat OAmI solution dynamically at 6000rpm on the perovskite layer MAPbI _2.91 Br _0.09 ;

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

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

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

Example 3

A perovskite solar cell with a hole transport layer modified by rare earth ions, the device structure from bottom to top is:

ITO/PTAA: Ce ³⁺ (0.5wt%)/MAPbI _2.91 Br _0.09 /OAmI/PCBM/BCP/Ag

The preparation method is as follows:

S1: Clean the ITO glass substrate with detergent, isopropanol solution, absolute ethanol and deionized water in sequence, and clean it with a UV-ozone cleaner for 40 minutes after drying;

S2: Spin-coat the hole transport layer PTAA on the cleaned ITO glass substrate, and then anneal at 100 degrees Celsius for 10 minutes;

S3: dynamically spin-coat CeCl ₃ (0.5wt%) solution on the hole transport layer PTAA at 3000rpm, and then anneal at 100 degrees Celsius for 10min;

S4: Spin-coat the perovskite precursor solution dynamically at 6000 rpm on the hole modifying layer CeCl ₃ , and then anneal at 100 degrees Celsius for 10 minutes;

S5: Spin-coat OAmI solution dynamically at 6000rpm on the perovskite layer MAPbI _2.91 Br _0.09 ;

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

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

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

Example 4

A perovskite solar cell with a hole transport layer modified by rare earth ions, the device structure from bottom to top is:

ITO/PTAA: Ce ³⁺ (1wt%)/MAPbI _2.91 Br _0.09 /OAmI/PCBM/BCP/Ag

The preparation method is as follows:

S1: Clean the ITO glass substrate with detergent, isopropanol solution, absolute ethanol and deionized water in sequence, and clean it with a UV-ozone cleaner for 40 minutes after drying;

S2: Spin-coat the hole transport layer PTAA on the cleaned ITO glass substrate, and then anneal at 100 degrees Celsius for 10 minutes;

S3: dynamically spin-coat CeCl ₃ (1wt%) solution on the hole transport layer PTAA at 3000rpm, and then anneal at 100 degrees Celsius for 10min;

S4: Spin-coat the perovskite precursor solution dynamically at 6000 rpm on the hole modifying layer CeCl ₃ , and then anneal at 100 degrees Celsius for 10 minutes;

S5: Spin-coat OAmI solution dynamically at 6000rpm on the perovskite layer MAPbI _2.91 Br _0.09 ;

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

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

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

Example 5

A perovskite solar cell with a hole transport layer modified by rare earth ions, the device structure from bottom to top is:

ITO/PTAA: Ce ³⁺ (5wt%)/MAPbI _2.91 Br _0.09 /OAmI/PCBM/BCP/Ag

The preparation method is as follows:

S1: Clean the ITO glass substrate with detergent, isopropanol solution, absolute ethanol and deionized water in sequence, and clean it with a UV-ozone cleaner for 40 minutes after drying;

S2: Spin-coat the hole transport layer PTAA on the cleaned ITO glass substrate, and then anneal at 100 degrees Celsius for 10 minutes;

S3: dynamically spin-coat CeCl ₃ (5wt%) solution on the hole transport layer PTAA at 3000rpm, and then anneal at 100 degrees Celsius for 10min;

S4: Spin-coat the perovskite precursor solution dynamically at 6000 rpm on the hole modifying layer CeCl ₃ , and then anneal at 100 degrees Celsius for 10 minutes;

S5: Spin-coat OAmI solution dynamically at 6000rpm on the perovskite layer MAPbI _2.91 Br _0.09 ;

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

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

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

It can be seen from Figures 1 and 2 that by introducing Ce ³⁺ perovskite devices, the photoelectric conversion efficiency (PCE), current density (J _SC ), open circuit voltage (V _OC ) and fill factor (FF) will be significantly improved. Improvement, when the Ce ³⁺ doping amount is 0.5wt%, its photoelectric conversion efficiency (PCE) can be increased by more than 27%.

It can be seen from Figure 3 that Ce ³⁺ exists on the perovskite lattice and surface, which indicates that Ce ³⁺ was successfully induced to migrate to the perovskite lattice and surface by annealing, and part of Ce ³⁺ replaced Pb ^{2 +} .

It can be seen from Figure 4 that, compared with the pristine MAPbI _2.91 Br _0.09 film, the Ce ³⁺ doped perovskite film has a larger grain size, better crystallinity, and fewer surface defects.

It can be seen from Figure 5 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 has not changed, so its forbidden band width has not changed. At the same time, it can also be seen in the trPL diagram that the carrier lifetime of the Ce ³⁺ doped perovskite device is significantly reduced, which indicates that the presence of Ce ³⁺ inhibits the recombination of carriers at the interface, which is beneficial to the hole and electron extraction.

It can be seen from Figure 6 that the Fermi level of the Ce ³⁺ doped perovskite device is higher, and the LUMO of the Ce ³⁺ doped perovskite device is closer to the LUMO of PCBM and Ag, making the electron mobility This improves the current density (J _SC ) of perovskite solar cells.

It can be seen from Fig. 7 that the dark current of the Ce ³⁺ doped perovskite device is lower, thereby increasing the open circuit voltage (V _OC ) of the perovskite solar cell.

It can be seen from Figure 8 that the photoelectric conversion efficiency (PCE) of the original perovskite device has dropped by 39% after 500h, while the Ce ³⁺ doped perovskite device remains at 92% after 500h Above, this shows that the doping of Ce ³⁺ effectively improves the stability of perovskite solar cells.

Claims (6)

1. The perovskite solar cell with the rare earth ion modified hole transport layer is characterized by sequentially comprising an ITO (indium tin oxide) conductive glass layer and rare earth ion Ce from bottom to top ³⁺ Modified poly [ bis (4-phenyl) (2, 4, 6-trimethylphenyl) amine](PTAA) as hole transport layer, MAPbI _2.91 Br _0.09 As Perovskite (PVSK), 9-octadecenyliodoamine (OAmI) as perovskite transport layer, [6,6,6%]-phenyl-C61-butyric acid isopropyl ester (PCBM) as electron transport layer, 2, 9-dimethyl-4, 7-biphenyl-1, 10-phenanthroline (BCP) as hole blocking layer and metal Ag electrode layer.

2. The perovskite solar cell with the rare earth ion modified hole transport layer according to claim 1, wherein the hole transport layer and the hole modification layer are prepared by the following steps:

s1: different mass fractions of CeCl ₃ Dissolving in absolute ethanol to obtain CeCl ₃ A solution;

s2: PTAA was dissolved in toluene solution to obtain PTAA solution.

3. The perovskite solar cell with the rare earth ion modified hole transport layer according to claim 2, wherein the specific steps in S1 are as follows:

0.2mg of CeCl ₃ Dissolved in 1ml of absolute ethanol to give 0.2mg/ml of CeCl ₃ A mother liquor;

from CeCl ₃ The mother solution was taken 500. Mu.l, 100. Mu.l, 50. Mu.l, 10. Mu.l and 0. Mu.l, and then 500. Mu.l, 900. Mu.l, 950. Mu.l, 990. Mu.l and 1ml of absolute ethanol were added thereto, respectively, to obtain 0-0.1mg/ml CeCl ₃ A solution;

CeCl described in S1 ₃ Respectively 0,0.1wt%,0.5wt%,1wt% and 5wt%;

the specific steps in S2 are as follows: 2mg of PTAA was dissolved in 1ml of toluene solution to give a 2mg/ml PTAA solution.

4. The rare earth ion modified cavity of claim 1Perovskite solar cell of a transport layer, characterized in that the perovskite MAPbI _2.91 Br _0.09 The preparation process comprises the following steps:

step1: mixing a mixture of 1:0.91:0.09 PbI ₂ MAI and MABr were dissolved in ACN solution and then an equal amount of methylamine solution was added to form 1.2M MAPbI _2.91 Br _0.09 A solution;

and 2, step: the solution was stirred on a magnetic stirrer for 3h and then filtered into a sample vial to produce the perovskite precursor solution.

5. The perovskite solar cell with the rare earth ion modified hole transport layer according to claim 4, characterized in that the specific operation in the step1 is as follows: 553.20mg of PbI ₂ 185.09mg of MAI and 4.03mg of MABr were dissolved in 800ml of ACN solution, and 800ml of methylamine solution were added to form MAPbI _3-x Br _x And (3) solution.

6. A preparation method of a perovskite solar cell with a hole transport layer modified by rare earth ions is characterized by comprising the following steps:

step1: sequentially using a detergent, an isopropanol solution, absolute ethyl alcohol and deionized water to clean the ITO glass substrate, drying, and then cleaning for 30-60min by using an ultraviolet ozone cleaning machine;

step2: spin-coating a hole transport layer PTAA on the cleaned ITO glass substrate, and then annealing at 100-150 ℃ for 10-15min;

step3: dynamic spin coating of CeCl onto hole transport layer PTAA at 2000-4000rpm ₃ The solution is annealed for 10-15min at 100-150 ℃;

step4: in the hole-modified layer CeCl ₃ Dynamically spin-coating perovskite precursor liquid at 3000-6000rpm, and then annealing at 100-150 ℃ for 10-15min;

step5: in perovskite layer MAPbI _2.91 Br _0.09 Dynamically spin-coating OAmI solution at 3000-6000 rpm;

step6: dynamically spin-coating PCBM solution on the perovskite transmission layer at 1000-2000 rpm;

step7: dynamically spin-coating BCP solution on the electron transport layer at 3000-6000 rpm;

step8: and (3) evaporating a metal electrode Ag on the hole blocking layer BCP in a vacuum coating machine, wherein the thickness is 100-120nm.

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