CN111883665B - Organic solar cell for constructing internal electric field by doping nano particles in charge transport layer and preparation method thereof - Google Patents

Abstract

The invention discloses an organic solar cell for constructing an internal electric field by doping nano particles in a charge transport layer and a preparation method thereof, which belong to the field of photoelectric devices and sequentially comprise a substrate, an electrode layer, an electron transport layer, an organic functional layer, a hole transport layer and a metal electrode layer from bottom to top, wherein the electron transport layer is doped with P-type semiconductor nano particles with the mass fraction of 0.5-3.5%, and the hole transport layer is doped with N-type semiconductor nano particles with the mass fraction of 0.5-3.5%. According to the invention, the internal electric field is constructed by doping the nano particles in the charge transport layer, so that the transport and collection efficiency of carriers is improved, the photoelectric conversion efficiency is improved, and the preparation method is simple and efficient, and is suitable for large-scale production.

Description

An organic solar cell that builds an internal electric field by doping nanoparticles in a charge transport layer and its preparation method

technical field

The invention belongs to the field of optoelectronic devices, and in particular relates to an organic solar cell capable of constructing an internal electric field by doping nano-particles in a charge transport layer and a preparation method thereof.

Background technique

Organic solar cells have a wide range of applications in many aspects such as resource conservation, environmental protection, energy utilization, and household daily use due to their low cost and flexibility. In order to meet the requirements of practical applications, organic solar cells should have high photoelectric conversion efficiency and long service life to achieve high-efficiency energy use. However, due to the complex mechanism of organic solar cells and the difficult separation of generated excitons, organic solar cells are often difficult to separate into free electrons and holes after photogenerated excitons are generated, resulting in low photoelectric conversion efficiency. Therefore, how to improve the separation of photogenerated excitons into free electrons and holes and reduce the energy loss caused by exciton recombination while ensuring the production of more photogenerated excitons has become the focus and difficulty of organic solar cell research.

SUMMARY OF THE INVENTION

The purpose of the present invention is: in view of the problem that the photo-generated excitons generated by the above-mentioned liquid organic solar cells are not easy to generate free electrons and holes and are easy to recombine and generate energy loss, and the low carrier transport efficiency leads to the problem of low device performance, the present invention provides a kind of An organic solar cell with an internal electric field constructed by doping nanoparticles in a charge transport layer and a preparation method thereof.

The technical scheme adopted in the present invention is as follows:

An organic solar cell that constructs an internal electric field by doping nanoparticles in a charge transport layer, including a substrate, an electrode layer, an electron transport layer, an organic functional layer, a hole transport layer and a metal electrode layer in order from bottom to top. The transport layer is doped with P-type semiconductor nanoparticles with a mass fraction of 0.5-3.5%, and the hole transport layer is doped with N-type semiconductor nanoparticles with a mass fraction of 0.5-3.5%.

The invention constructs an internal electric field by doping nano-particles inside the charge transport layer, improves the transmission and collection efficiency of carriers, has good performance of improving the photoelectric conversion efficiency, and the preparation method is simple and efficient, and is suitable for large-scale production.

Preferably, the raw material of the electron transport layer is any one or more of PC61BM, ZnO, MoOx, NiOx, TiO2, SnOx, PFN, PEIE and PANIO, wherein x is 2 or 3, and the electron The material of the P-type semiconductor nanoparticles doped in the transport layer is any one or more of Cu1.8S, Cu2O, TiO2, indium, aluminum, boron, and manganese.

Preferably, the raw material of the hole transport layer is any one or more of MnO3, PEDOT:PSS, CuSCN, CuI, NiOm, TiO2, SnOx, wherein x is 2 or 3, and m is The value is 2 or 4; the material of the N-type semiconductor nanoparticles doped in the hole transport layer is any one or more of arsenic, phosphorus, antimony, Ta2O5, and silver.

Preferably, the raw material of the electrode layer is any one of indium tin oxide (ITO), gold, silver, aluminum, copper, silver nanowires, calcium and conductive polymer film electrodes, silver nanowires and conductive polymer films species, with a thickness of 2 to 30 nm.

Preferably, the organic functional layer is any one of organic donor-acceptor material bulk heterojunction PBDB-T:ITIC, PM6:Y6, PBDB-T:IT4F, PBTTT:PCBM, P3HT:PCBM, C60:CuPc , the thickness is 100nm-200nm.

Preferably, the raw material of the metal electrode layer is any one of indium tin oxide (ITO), gold, silver, copper, aluminum, calcium electrodes, silver nanowires and conductive polymer films, with a thickness of 50-150 nm.

A preparation method of an organic solar cell for constructing an internal electric field by doping nanoparticles in a charge transport layer, comprising the following steps:

(1) Cleaning the glass substrate with ITO electrode, and drying it with ultraviolet oxidation treatment;

(2) spin-coating an electron transport layer doped with P-type semiconductor nanoparticles on a glass substrate, and annealing for use;

(3) spin-coating the organic donor-acceptor solution on the electron transport layer to form an organic functional layer, and annealing for use;

(4) spin-coating a hole transport layer doped with N-type semiconductor on the organic functional layer, and annealing for use;

(5) A silver electrode was vapor-deposited on the hole transport layer.

Preferably, the specific steps of step (2) are: under atmospheric conditions, place the glass substrate on a spin coater, drop 40-60 ul and add 0.5-3.5% of P-type semiconductor nanoparticles with a mass fraction of 0.5-3.5%. The solution of the raw material of the electron transport layer is controlled at a rotating speed of 4500-5500 rpm and a time of 50-70 s, and then annealed, and the annealing temperature is controlled at 140-160° C. and the time is 10-20 min.

Preferably, the specific steps of step (3) are: transferring the experimental device to the glove box, spin-coating an organic functional layer on the electron transport layer doped with P-type semiconductor nanoparticles under an inert atmosphere, and controlling the rotational speed to be 3500 -4500rpm, the time is 15-25s, and then annealing treatment is carried out, the annealing temperature is controlled at 120-140 ℃, and the time is 10-20min.

Preferably, the specific steps of step (4) are as follows: transfer the spin-coated organic functional layer to a vacuum evaporation device, and evaporate a layer doped with a The raw material solution of the N-type semiconductor nanoparticle hole transport layer with a mass fraction of 0.5-3.5% is cooled in a vacuum environment for 20-30 minutes.

Compared with the prior art, the beneficial effects of the present invention are:

(1) In the present invention, P-type semiconductor nanoparticles are doped in the electron transport layer, and N-type semiconductor nanoparticles are doped in the hole transport layer, so that an internal electric field can be constructed after the passage is formed, so that the excitons are separated into free electron holes. The ability is increased, and the carrier mobility of electrons and holes is improved, so that the device can improve the performance;

(2) The present invention changes the Fermi level of the transport layer by doping the electron transport layer and the hole transport layer, and can achieve energy level matching between the transport layer and the organic functional layer by controlling the doping concentration, Facilitate the collection of carriers;

(3) In the present invention, using the traditional organic solar cell structure and combining a simple and efficient spin coating process, only a small amount of doping in the charge transport layer can obtain higher photoelectric conversion capability, and the cost performance is extremely high; The large-scale industrial fabrication of organic solar cells as well as detectors in other fields is instructive.

Description of drawings

Fig. 1 is the structural representation of the present invention;

Fig. 2 is a graph of carrier transport and energy level changes before and after doping semiconductor nanoparticles in the charge transport layer;

3 is a schematic structural diagram of the electron donor material PBDB-T and the electron acceptor material ITIC used in the present invention;

FIG. 4 is a comparison of the JV curves of Example 1 and Example 2.

The figures are marked as: 1-substrate, 2-electrode layer, 3-electron transport layer, 4-organic functional layer, 5-hole transport layer, 6-metal electrode layer.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

The present invention solves the problems that the photo-generated excitons generated by the organic solar cell are not easy to generate free electrons and holes and are easy to recombine, resulting in energy loss, and low carrier transport efficiency leads to low device performance. Doping low-concentration P-type semiconductor nanoparticles in the electron transport layer is easy to lose positive electron charge, and doping low-concentration N-type semiconductor nanoparticles in the hole transport layer is easy to obtain negative electron charge, so that inside the active layer The formation of an electric field has the effect of electric field force on the free electrons and holes generated by the active layer, which is conducive to the transport and collection of free electrons and holes, reduces the carrier concentration of the active layer to the acceptor interface, and promotes the separation of excitons. And changing the energy levels of the electron transport layer and the hole transport layer, the energy level structure between the charge transport layer and the active layer is more matched. (as shown in picture 2).

Example 1

An organic solar cell that constructs an internal electric field by doping nanoparticles in a charge transport layer, as shown in Figure 1, includes a substrate, the substrate has an electrode layer, and the electrode layer is plated with doped P-type semiconductor nanoparticles for electron transport. layer, the electron transport layer of the doped P-type semiconductor nanoparticles is spin-coated with an organic functional layer and a hole transport layer of the doped N-type semiconductor nanoparticles in turn from bottom to top, and the doped N-type semiconductor nanoparticles A metal electrode layer is plated on the hole transport layer.

Wherein, the substrate is a glass substrate.

The electrode layer adopts the ITO transparent conductive electrode on the glass substrate.

The electron transport layer doped with P-type semiconductor nanoparticles adopts a ZnO film with a thickness of 10 nm doped with 2wt% Cu2O nanoparticles.

The organic functional layer 5 adopts a PBDB-T:ITIC (see Figure 3) bulk heterojunction with a thickness of 150 nm.

The hole transport layer 6 is a 10nm thick MnO3 thin film doped with 2wt% arsenic nanoparticles.

The metal electrode layer 7 is a silver electrode with a thickness of 100 nm.

A preparation method of an organic solar cell for constructing an internal electric field by doping nanoparticles in a charge transport layer, comprising the following preparation steps:

1. Cleaning the substrate: Put the glass substrate with the conductive electrode 2 into detergent, acetone, deionized water, and isopropanol in turn, ultrasonically clean for 15 minutes each time, and then dry it with an inert gas and oxidize it with ultraviolet light for 15 minutes. .

2. Spin coating the electron transport layer of doped P-type semiconductor nanoparticles: under atmospheric conditions, the glass substrate is placed on the spin coater, and 50ul of ZnO solution added with 2wt% Cu2O nanoparticles is dropped, and the control speed is 5000rpm and the time is 5000rpm. 60s, and then annealed, the annealing temperature was controlled at 150°C, and the time was 15min.

3. Spin-coating the organic functional layer: At this time, the experimental device was transferred to the glove box, and an organic functional layer was spin-coated on the electron transport layer doped with P-type semiconductor nanoparticles under a nitrogen atmosphere, and the rotational speed was controlled at 4000 rpm and the time 20s, and then annealing treatment, the annealing temperature is controlled at 130 ° C, the time is 15min.

4. Evaporation of doped N-type semiconductor nanoparticle hole transport layer: transfer the spin-coated organic functional layer to a vacuum evaporation equipment, and evaporate a layer of doped N-type semiconductor nanoparticle in an environment with a vacuum degree of less than 3×10-3Pa. The N-type semiconductor nanoparticle MnO3 was then cooled in a vacuum environment for 30 min.

5. Evaporating metal electrode 6: Evaporating a layer of Ag electrode in an environment where the degree of vacuum is less than 3.0×10-3Pa.

Under standard test conditions (AM 1.5, 100mW/cm2), the measured open circuit voltage (VOC) of the device = 0.884577V, short circuit current (JSC) = 14.5886mA/cm2, fill factor (FF) = 0.619375, energy conversion efficiency ( PCE) = 7.99286%.

Example 2: Comparative Example

On the basis of Example 1, the difference between this example and Example 1 is that the electron transport layer and the hole transport layer are not doped, which is not enough to build the internal electric field of the device. Solar cells, and Example 1 constitute a control group.

The substrate is glass substrate, the electrode layer is ITO electrode, the electron transport layer is ZnO, the organic functional layer is PBDB-T:ITIC bulk heterojunction, the hole transport layer is MnO3, and the electrode layer 6 is silver electrode.

The specific preparation method is as follows:

1. Cleaning the substrate: Put the glass substrate with the conductive electrode 2 into detergent, acetone, deionized water, and isopropanol in turn, ultrasonically clean for 15 minutes each time, and then dry it with an inert gas and oxidize it with ultraviolet light for 15 minutes. .

2. Spin coating electron transport layer: under atmospheric conditions, place the glass substrate on the spin coater, drop 50ul ZnO solution, control the rotation speed to 5000rpm and the time for 60s, and then carry out annealing treatment, the annealing temperature is controlled at 150℃, and the time is 15min.

3. Spin-coating the organic functional layer: At this time, the experimental device was transferred to the glove box, and an organic functional layer was spin-coated on the electron transport layer in a nitrogen atmosphere. The annealing temperature was controlled at 130 °C and the time was 15 min.

4. Evaporation of hole transport layer: transfer the spin-coated organic functional layer to a vacuum evaporation equipment, evaporate a layer of MnO3 in an environment with a vacuum degree of less than 3×10-3Pa, and then cool it in a vacuum environment for 30min.

5. Evaporating metal electrode 6: Evaporating a layer of Ag electrode in an environment where the degree of vacuum is less than 3.0×10-3Pa.

Under standard test conditions (AM 1.5, 100mW/cm2), the measured open circuit voltage (VOC) of the device = 0.868293V, short circuit current (JSC) = 13.9225mA/cm2, fill factor (FF) = 0.582131, energy conversion efficiency ( PCE) = 7.03727%.

The above-mentioned embodiments only represent specific implementations of the present application, and the descriptions thereof are specific and detailed, but should not be construed as limiting the protection scope of the present application. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the technical solution of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application.

Claims (8)

1. An organic solar cell for constructing an internal electric field by doping nanoparticles in a charge transport layer, comprising a substrate, an electrode layer, an electron transport layer, an organic functional layer, a hole transport layer and a metal electrode layer in sequence from bottom to top, wherein characterized in that the electron transport layer is doped with P-type semiconductor nanoparticles with a mass fraction of 0.5-3.5%, and the hole transport layer is doped with N-type semiconductor nanoparticles with a mass fraction of 0.5-3.5%; The raw material of the electron transport layer is any one or more of PC ₆₁ BM, ZnO, MoO _x , NiO _x , TiO ₂ , SnO _x , PFN, PEIE and PANIO, wherein x is 2 or 3, The material of the electron transport layer doped P-type semiconductor nanoparticles is any one or more of Cu _1.8 S, Cu ₂ O, TiO ₂ , indium, aluminum, boron, and manganese; The raw material of the hole transport layer is any one or more of MnO ₃ , PEDOT:PSS, CuSCN, CuI, NiO _m , TiO ₂ , and SnO _x , wherein x is 2 or 3, and the value of m is 2 or 3. The value is 2 or 4; the material of the N-type semiconductor nanoparticles doped in the hole transport layer is any one or more of arsenic, phosphorus, antimony, Ta ₂ O ₅ and silver. 2 . The organic solar cell according to claim 1 , wherein the charge transport layer is doped with nanoparticles to construct an internal electric field, wherein the electrode layer is made of indium tin oxide, gold, silver, aluminum, and copper. , any one of electrodes, silver nanowires and conductive polymer films in silver nanowires, calcium and conductive polymer films, with a thickness of 2-30 nm. 3 . The organic solar cell according to claim 1 , wherein the charge transport layer is doped with nanoparticles to construct an internal electric field, wherein the organic functional layer is an organic donor-acceptor material bulk heterojunction PBDB-T. :ITIC, PM6:Y6, PBDB-T:IT4F, PBTTT:PCBM, P3HT:PCBM, C60:CuPc, the thickness is 100nm-200nm. 4 . The organic solar cell according to claim 1 , wherein the charge transport layer is doped with nanoparticles to construct an internal electric field, wherein the metal electrode layer is made of gold, silver, copper, aluminum, and calcium electrodes. , any one of silver nanowires, the thickness is 50-150nm. 5. The method for preparing an organic solar cell for constructing an internal electric field by doping nanoparticles in a charge transport layer according to any one of claims 1-4, wherein the method comprises the following steps: (1) Cleaning the glass substrate with ITO electrode, and drying it with ultraviolet oxidation treatment; (2) spin-coating an electron transport layer doped with P-type semiconductor nanoparticles on a glass substrate, and annealing for use; (3) spin-coating the organic donor-acceptor solution on the electron transport layer to form an organic functional layer, and annealing for use; (4) spin-coating a hole transport layer doped with N-type semiconductor on the organic functional layer, and annealing for use; (5) A silver electrode was vapor-deposited on the hole transport layer. 6. a kind of preparation method of the organic solar cell that builds internal electric field by doped nano-particle in charge transport layer according to claim 5, it is characterized in that, the concrete step of step (2) is: under atmospheric condition, will The glass substrate was placed on the spin coater, and 40-60ul was added to the solution of electron transport layer material doped with P-type semiconductor nanoparticles with a mass fraction of 0.5-3.5%. The control speed was 4500-5500rpm and the time was 50- 70s, and then carry out annealing treatment, the annealing temperature is controlled at 140-160°C, and the time is 10-20min. 7. a kind of preparation method of the organic solar cell that builds internal electric field by doping nano-particles in charge transport layer according to claim 6, it is characterized in that, the concrete step of step (3) is: the experimental device is transferred to glove In the box, spin-coat an organic functional layer on the electron transport layer doped with P-type semiconductor nanoparticles in an inert atmosphere. 120-140℃, the time is 10-20min. 8. a kind of preparation method of the organic solar cell that builds internal electric field by doping nano-particles in charge transport layer according to claim 7, it is characterized in that, the concrete step of step (4) is: will spin-coated organic solar cells The functional layer is transferred to a vacuum evaporation equipment, and a hole transport layer doped with N-type semiconductor nanoparticles with a mass fraction of 0.5-3.5% is evaporated in an environment with a vacuum degree of less than (2-5)×10 ^-3 Pa. The raw material solution was then cooled under vacuum for 20-30min.

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