CN113258003B

CN113258003B - Organic photovoltaic device preparation process based on metal nanoparticle magnetic thermal effect annealing process

Info

Publication number: CN113258003B
Application number: CN202110590423.3A
Authority: CN
Inventors: 于军胜; 张大勇; 杨根杰; 李嘉文
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2022-04-15
Anticipated expiration: 2041-05-28
Also published as: CN113258003A

Abstract

The invention relates to a preparation process of an organic photovoltaic device based on a metal nanoparticle magnetic thermal effect annealing process, wherein an iron oxide nanoparticle doped photoactive layer is prepared by doping a small amount of iron oxide nanoparticle solution into a photoactive layer solution during solution preparation and carrying out common spin coating, a solar cell device is placed in a lead coil which is provided with alternating current after the preparation and film forming, the magnetic heat effect of the metal thin layer is utilized to realize the whole non-contact type direct heating device, the effective thermal annealing treatment is directly carried out from the optical active layer, the device has better crystallization property and internal charge transmission property, the short-circuit current property of the device can be effectively improved, secondly, the iron oxide nano-particle layer can effectively improve the contact characteristic between the optical active layer and the electrode buffer layer, realize the inhibition of the energy loss of the photovoltaic device, improve the open-circuit voltage characteristic of the device, and finally, the weak magneto-optical effect of the magnetic nanoparticles can further improve the absorption characteristic of the optical active layer to light waves.

Description

Organic photovoltaic device preparation process based on metal nanoparticle magnetic thermal effect annealing process

Technical Field

The invention belongs to the field of organic polymer photovoltaic devices or organic semiconductor thin-film solar cells, and particularly relates to a preparation process of an organic photovoltaic device based on a metal nanoparticle magnetic thermal effect annealing process.

Background

With the rapid development of the world economy and the gradual update of the scientific technology, the development and the utilization of novel energy are the basic needs and the key development directions of the current social development. At present, the novel clean energy mainly comprises: under the premise of wind energy, heat energy, nuclear energy, solar energy and the like, the solar energy is widely concerned by researchers by the characteristics of inexhaustible values, complete greenness, no pollution and the like. Regarding the utilization of solar energy, at present, the photovoltaic technology is mainly divided into two categories, namely a photo-thermal technology and a solar photovoltaic family as an energy acquisition means for directly converting light energy into electric energy, and the solar photovoltaic family becomes the frontier hot research field by the unique energy acquisition mode and effective electric energy generation. The development of photovoltaic research mainly goes through a first-generation silicon-based photovoltaic cell, a second-generation inorganic compound photovoltaic cell and a third-generation thin-film photovoltaic cell which mainly comprises organic substances, perovskite substances and the like at present, wherein a third-generation thin-film organic solar photovoltaic device becomes an indispensable part in the research of the photovoltaic field at present due to the characteristics of good flexibility, large-area production, light weight, no toxicity and the like, and is also considered as an ideal wearable electronic skin function equipment prototype.

In recent years, the Y-series non-fullerene acceptor based organic solar cells have rapidly improved performance to over 18%, mainly due to their ideal optical and electrical properties ensuring a sufficiently high short circuit current density and fill factor for this type of device, but a low open circuit voltage compared to these two characteristics remains a big drawback of this type of photovoltaic device. Based on this, the development of new materials or the design of novel device structures to improve the open circuit voltage of organic photovoltaic devices has become a key issue for further commercialization of organic photovoltaics.

At present, the performance of Y-series non-fullerene organic photovoltaic devices is directly behind the performance (> 20%) of traditionally commercialized silicon-based photovoltaic devices. In recent 3 years, a great deal of novel material synthesis based on Y series non-fullerene materials also becomes a main research target of researchers, however, the rapid material synthesis development leads to the fact that the research on the optical active layer of the device and the internal working mechanism of the device is slightly lacked. Therefore, the research on how to control the internal crystallization condition of the organic photoactive layer and how to optimize the contact condition between different functional layers is an effective way for improving the power conversion efficiency of the organic solar cell and improving the stability of the device, and is also one of the key points and difficulties of the research in the field of the organic solar cell at present.

An organic photovoltaic device of a metal nanoparticle magnetic thermal effect annealing process belongs to the field of organic semiconductor thin-film solar cells, and adopts an inverted structure, wherein a substrate, a transparent conductive cathode ITO, a ZnO cathode buffer layer, an iron oxide nanoparticle-doped optical activity layer, a MoO3 anode buffer layer and a metal anode are sequentially arranged from bottom to top; the light activity layer doped with the iron oxide nano particles is prepared by doping a small amount of iron oxide nano particle solution into the light activity layer solution for common spin coating during solution preparation, placing a solar cell device into a conducting coil with alternating current after film formation, realizing non-contact direct heating of the whole device by utilizing the magnetocaloric effect of a metal thin layer, and directly carrying out effective thermal annealing treatment from the light activity layer.

Disclosure of Invention

The invention aims to solve the defects in the prior art, and the invention adopts the following technical scheme for realizing the aim:

a preparation process of an organic photovoltaic device based on a metal nanoparticle magnetic thermal effect annealing process comprises the following steps:

step 1: cleaning a substrate consisting of a transparent substrate and a transparent conductive cathode ITO, and drying the substrate by using nitrogen after cleaning;

step 2: rotationally coating, printing or spraying a cathode buffer layer ZnO sol-gel precursor solution on the surface of the transparent conductive cathode ITO, and carrying out thermal annealing at the annealing temperature of 200 ℃ for 2H;

and step 3: dropwise adding PM6, Y6: the Fe3O4 mixed solution is arranged on the ZnO buffer layer, and a mixed light active layer is prepared by a spin coating process, the rotation speed during spin coating is 4000rpm, the time is 40s, and the coating thickness is 110 nm;

and 4, step 4: transferring the device into a lead coil with high-frequency alternating current, and performing thermal annealing treatment on the photo-active layer by using a magnetocaloric effect, wherein the annealing temperature is 90 ℃ and the annealing time is 10 min;

and 5: under the condition that the vacuum degree is 3 × 10-3Pa, evaporating MoO3 on the surface of the optical active layer to prepare an anode buffer layer;

step 6: and evaporating the metal anode under the condition of vacuum degree of 3 × 10-4 Pa.

Preferably, the thermal annealing temperature of the cathode buffer layer in the step (2) is 200-250 ℃, and the time is 1-2 h.

Preferably, the thermal annealing and low-temperature baking modes adopt one or more of eddy current heat generation, constant-temperature heating, oven heating, far infrared heating and hot air heating.

Compared with the prior art, the invention has the beneficial effects that:

1. the added iron oxide magnetic nanoparticles can play a role of a solid additive, can effectively regulate and control the appearance of the photoactivation layer, fill up the internal defects of the photoactivation layer, promote the charge separation and transmission in the photoactivation layer, effectively inhibit the composition of photon-generated carriers, and further improve the current output characteristic of the device.

2. The iron oxide magnetic nanoparticles can play a role of an energy regulator in the optical active layer, and the surface energy level of the optical active layer is regulated and controlled through the self energy level characteristics of the nanoparticles, so that the optical active layer is in good contact with the electrode buffer layer, and the open-circuit voltage characteristics of the device are improved. Furthermore, the iron oxide magnetic nanoparticles have a certain magneto-optical effect, and when the device is in a strong magnetic field, the working current output of the device is larger, so that the device can obtain excellent characteristics of high open-circuit voltage and high short-circuit current.

3. The magnetic nanoparticles can generate heat by self by utilizing a magnetocaloric effect in an alternating magnetic field, and by utilizing the characteristic, the internal direct thermal annealing treatment of the photoactive layer, namely annealing from self to outside can be realized.

Detailed Description

Example 1:

1. cleaning a base plate with the surface roughness less than 1nm and consisting of a transparent substrate and a transparent conductive cathode ITO, and drying by using nitrogen after cleaning;

2. rotationally coating ZnO on the surface of the transparent conductive cathode ITO; the rotating speed is 5000rpm, the time is 50s, the coating thickness is 40nm, a cathode buffer layer is prepared, and the formed film is subjected to thermal annealing treatment, wherein the temperature of the thermal annealing treatment is 200 ℃, and the time is 2 h;

3. dripping PM6: Y6 solution on the cathode buffer layer, wherein the ratio of PM6: Y6 is 1:1, the concentration of the solution is 6mg/ml, preparing the photoactive layer by adopting a spin coating process, wherein the rotation speed is 4000rpm, the time is 40s, and the coating thickness is 90 nm;

4. placing the PM6: Y6 photoactive layer on a constant temperature heating table at 90 ℃ under an atmospheric environment, and heating and annealing for 10 min;

5. an anode buffer layer MoO3 is vapor-plated on the photoactive layer, and the thickness of the vapor-plated anode buffer layer MoO3 is 15 nm;

6. evaporating metal anode Ag on the anode buffer layer, wherein the thickness of the evaporated metal anode Ag is 100 nm;

7. under standard test conditions: AM 1.5,100mW/cm2, the open-circuit Voltage (VOC) of the device was measured to be 0.83V, the short-circuit current (JSC) was measured to be 22.3mA/cm2, the Fill Factor (FF) was measured to be 0.69, and the Photoelectric Conversion Efficiency (PCE) was measured to be 12.77%.

Example 2:

2. rotationally coating ZnO on the surface of the transparent conductive cathode ITO to prepare a cathode buffer layer; the rotating speed is 5000rpm, the time is 50s, the coating thickness is 40nm, the temperature for carrying out thermal annealing treatment on the formed film is 200 ℃, and the time is 2H;

3. preparing a mixed light active layer by adopting a spin coating process, coating a PM6: Y6: Fe3O4 solution on the mixed light active layer, wherein the ratio of PM6: Y6: Fe3O4 in the PM6: Y6: Fe3O4 solution is 1:1: 0.1; the concentration of the solution is 6mg/ml, the rotation speed during spin coating is 4000rpm, the time is 40s, and the coating thickness is 110 nm;

4. placing the PM6: Y6: Fe3O4 optical active layer in a lead coil which is electrified with alternating current under atmospheric environment for magnetic thermal annealing, wherein the annealing temperature is 90 ℃, and the annealing time is 10 min;

5, evaporating and plating an anode buffer layer on the photoactive layer, wherein the thickness of MoO3 is 15 nm;

6. the thickness of the metal anode Ag evaporated on the anode buffer layer is 100 nm;

7. under standard test conditions: AM 1.5,100mW/cm2, the open-circuit Voltage (VOC) of the device was measured to be 0.86V, the short-circuit current (JSC) was measured to be 21.13mA/cm2, the Fill Factor (FF) was measured to be 0.65, and the Photoelectric Conversion Efficiency (PCE) was measured to be 11.81%.

Example 3:

2. coating ZnO on the surface of the transparent conductive cathode ITO in a rotating mode to prepare a cathode buffer layer, wherein the rotating speed of the cathode buffer layer is 5000rpm, the coating ZnO is coated for 50s, the thickness of the cathode buffer layer is 40nm, and the formed film is subjected to thermal annealing treatment; the annealing temperature is 200 ℃, and the annealing time is 2H;

3. preparing a mixed light active layer by adopting a spin coating process, coating PM6: Y6: Fe3O4 solution on the mixed light active layer, wherein the ratio of PM6: Y6: Fe3O4 in the PM6: Y6: Fe3O4 solution is 1:1:0.2, the solution concentration is 6mg/ml, the rotation speed is 4000rpm, the time is 40s, and the coating thickness is 110 nm;

4. placing the PM6: Y6: Fe3O4 optical active layer in a lead coil which is electrified with alternating current under the atmospheric environment, and carrying out magnetocaloric annealing at the temperature of 90 ℃ for 10 min;

5, evaporating an anode buffer layer on the optical active layer, wherein the thickness of the evaporated anode buffer layer MoO3 is 15 nm; (ii) a

7. under standard test conditions: AM 1.5,100mW/cm2, the open-circuit Voltage (VOC) of the device was measured to be 0.86V, the short-circuit current (JSC) was measured to be 22.35mA/cm2, the Fill Factor (FF) was measured to be 0.68, and the Photoelectric Conversion Efficiency (PCE) was measured to be 13.07%.

Example 4:

2. rotationally coating ZnO on the surface of the transparent conductive cathode ITO to prepare a cathode buffer layer; the rotating speed is 5000rpm, the time is 50s, the coating thickness is 40nm, the formed film is subjected to thermal annealing treatment, the temperature of the annealing treatment is 200 ℃, and the time is 2H;

3. preparing a mixed light active layer by adopting a spin coating process, coating a PM6: Y6: Fe3O4 solution on the mixed light active layer, wherein the ratio of PM6: Y6: Fe3O4 in the PM6: Y6: Fe3O4 solution is 1:1:0.3, and the solution concentration is 6 mg/ml; the rotating speed of spin coating is 4000rpm, the time is 40s, and the coating thickness is 110 nm;

5, evaporating an anode buffer layer MoO3 on the photoactive layer, wherein the thickness of the evaporated anode buffer layer MoO3 is 15 nm;

7. under standard test conditions: AM 1.5,100mW/cm2, the open-circuit Voltage (VOC) of the device was measured to be 0.87V, the short-circuit current (JSC) was measured to be 24.76mA/cm2, the Fill Factor (FF) was measured to be 0.71, and the Photoelectric Conversion Efficiency (PCE) was measured to be 15.29%.

Example 5:

2. rotationally coating ZnO on the surface of the transparent conductive cathode ITO to prepare a cathode buffer layer, wherein the rotational speed is 5000rpm, the time is 50s, the coating thickness is 40nm, and performing thermal annealing treatment on the formed film, wherein the annealing temperature is 200 ℃, and the annealing time is 2H;

3. preparing a mixed light active layer by adopting a spin coating process, coating a PM6: Y6: Fe3O4 solution on the mixed light active layer, wherein the ratio of PM6: Y6: Fe3O4 in the PM6: Y6: Fe3O4 solution is 1:1:0.4, the solution concentration is 6mg/ml, the rotating speed in the spin coating process is 4000rpm, the time is 40s, and the coating thickness is 110 nm;

7. under standard test conditions: AM 1.5,100mW/cm2, the open-circuit Voltage (VOC) of the device was measured to be 0.86V, the short-circuit current (JSC) was measured to be 21.12mA/cm2, the Fill Factor (FF) was measured to be 0.66, and the Photoelectric Conversion Efficiency (PCE) was measured to be 11.99%.

Example 6:

2. rotationally coating ZnO on the surface of the transparent conductive cathode ITO to prepare a cathode buffer layer, wherein the rotational speed of spin coating is 5000rpm, the time is 50s, the coating thickness is 40nm, and performing thermal annealing treatment on the formed film, wherein the annealing temperature is 200 ℃ and the annealing time is 2H;

3. preparing a mixed light active layer by adopting a spin coating process, coating a PM6: Y6: Fe3O4 solution on the mixed light active layer, wherein the ratio of PM6: Y6: Fe3O4 in the PM6: Y6: Fe3O4 solution is 1:1:0.3, the concentration of the solution is 6mg/ml, the rotating speed in the spin coating process is 4000rpm, the time is 40s, and the coating thickness is 110 nm;

4. placing the light active layer of PM6: Y6: Fe3O4 on a constant temperature heating table at 90 ℃ for heating and annealing for 10min under the atmospheric environment;

7. under standard test conditions: AM 1.5,100mW/cm2, the open-circuit Voltage (VOC) of the device was measured to be 0.86V, the short-circuit current (JSC) 23.76mA/cm2, the Fill Factor (FF) was measured to be 0.69, and the Photoelectric Conversion Efficiency (PCE) was measured to be 14.10%.

It can be seen that: compared with an organic solar cell which is not processed and prepared, namely the organic solar cell prepared in the example 1, the Jsc of the organic solar cell prepared by introducing the magnetic nanoparticles and utilizing the magnetocaloric effect annealing is increased, the FF is improved, and the Voc is improved; the magnetic nanoparticle magnetic thermal annealing method is used for well optimizing the film forming of the optical active layer of the device and effectively contributing to the optical absorption of the device by the weak magnetic optical effect, and then the magnetic nanoparticles are used for optimizing the energy level of the optical active layer and inhibiting the internal energy loss of the active layer, so that the open-circuit voltage of the device is further improved, and the energy conversion efficiency of the organic photovoltaic device is finally improved; further, by comparing the standard device, namely example 1, with the organic photovoltaic device prepared by the nanoparticle magnetic thermal annealing and conventional nanoparticle annealing method, namely examples 4 and 6, it is illustrated that the addition of the magnetic nanoparticles has an obvious optimization effect on the organic photovoltaic device, and the magnetic thermal annealing can prepare an active layer film with more excellent quality compared with the conventional thermal annealing, and finally, the energy conversion efficiency of the device is greatly improved by the addition of the magnetic nanoparticles and the regulation and control of the magnetic thermal annealing method.

The present invention has been illustrated by the above embodiments, but it should be understood that the above embodiments are for illustrative and descriptive purposes only and are not intended to limit the invention to the scope of the described embodiments. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many variations and modifications may be made in accordance with the teachings of the present invention, which variations and modifications are within the scope of the present invention as claimed; the scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A preparation process of an organic photovoltaic device based on a metal nanoparticle magnetic thermal effect annealing process is characterized by comprising the following steps:

2. The preparation process of the organic photovoltaic device based on the metal nanoparticle magnetocaloric effect annealing process, according to claim 1, wherein the preparation process comprises the following steps:

the cathode buffer layer thermal annealing adopts one or more of eddy current heat generation, constant temperature heating, oven heating, far infrared heating and hot air heating.