CN106450005A - Preparation method for rare earth up-conversion nano-disk polymer solar cell - Google Patents

Abstract

The invention discloses a method for preparing a rare earth up-conversion nano-disk polymer solar cell, which comprises the following steps: synthesis of nanoparticles with KGdF ₄ :Yb ³⁺ /Er ³⁺ disc structure; nano KGdF ₄ :Yb ³⁺ /Er Synthesis of nanoparticles with ³⁺ disk structure; and preparation of nanodisk polymer solar cells. A method for preparing rare earth co-doped up-conversion nano-disc polymer solar cells proposed by the present invention directly modifies the disc-shaped nanoparticles doped with rare earth ions on the electrode surface, increases the light absorption area, and effectively reduces the photogenerated electrons and The recombination of holes broadens the absorption range of sunlight, and improves the solar energy conversion efficiency and filling factor compared with the prior art. The preparation process is simple and repeatable, and is worthy of popularization.

Description

A preparation method of rare earth up-conversion nanodisk polymer solar cell

technical field

The invention relates to the technical field of solar cell preparation, in particular to a method for preparing a rare earth up-conversion nano-disk polymer solar cell.

Background technique

It is estimated that by 2050, the world's energy consumption will be more than twice the current consumption. With the development of society relying on energy, traditional energy sources such as coal, oil, natural gas and other mineral energy are far from meeting the needs of human development, which has caused increasingly severe social and environmental problems. Solar energy is clean, non-polluting, inexhaustible green energy, and solar cells that convert solar energy into electrical energy have attracted more and more research interest. Countries also regard the development and utilization of solar energy as a national strategic goal. Silicon-based solar cells have high efficiency, but the production energy consumption is high, and the stability of sensitized solar cells is poor. Compared with inorganic solar cells, polymer solar cells have the advantages of low cost, simple process, strong design, and can be fabricated into flexible devices. The main problems are: narrow light absorption range and poor light utilization efficiency, therefore, the performance of solar cells can be effectively improved through the modification of materials.

Rare earth ions (Ln ³⁺ ) contain 4f electrons with similar energy levels and are not filled, and are shielded by 5s2p6 electrons from the external field, so their coordination field effect is small, and they have rich energy levels and electronic transition characteristics. Some rare earth ions After being excited, it can emit characteristic fluorescence through df and ff orbital transitions. This is because it has unique properties in terms of light, electricity, and magnetism, rich electronic energy levels and long lifetimes of excited states, and emits fluorescence in a wide range including ultraviolet light, visible light and infrared light. my country is rich in rare earth resources, accounting for more than 80% of the world's detected reserves. It is of far-reaching significance for my country to carry out in-depth research on the application of rare earth compounds in solar cells. The study found that by co-doping Ln ³⁺ in the same matrix material, the down-conversion fluorescence under ultraviolet light and the up-conversion fluorescence excited by infrared can be realized at the same time. If the emitted fluorescence can be combined with the light absorption of the active layer of polymer solar cells In principle, the matching range can broaden the absorption of sunlight by polymer solar cells and improve the photoelectric conversion efficiency.

The choice of matrix material is crucial for the fluorescence emission of Ln ³⁺ -doped nanoparticles. Generally speaking, the following three conditions need to be met: 1. Low phonon energy, which can minimize the energy loss caused by non-radiative relaxation; 2. Good chemical and thermal stability; 3. The lattice parameters of the matrix It is close to the dopant ion lattice parameter. Relatively speaking, inorganic fluorides have low phonon energy (350cm ^-1 ), and are often used as matrix materials for upconversion nano-ions. The most common one is hexagonal NaYF ₄ , but it is easy to cause phase transition, which greatly reduces the fluorescence efficiency of the material. The KGdF ₄ matrix is cubic in the range of 3.7-35nm, and the lowest excited state (6P7/2) of Gd ³⁺ is located above the ultraviolet region, which greatly reduces the cross relaxation in the energy transfer process. Through morphological control, nanodisk-like structures were synthesized to enhance the absorption of sunlight due to their large surface area. On the basis, the synthesized rare earth doped KGdF ₄ is used as a matrix material in polymer solar cells, which can broaden the light absorption range of the cell, improve the conductivity of the material, and effectively increase the photocurrent density.

In the existing patented technologies, most of the synthesized materials with nanostructures are applied to the organic active layer, which can improve the absorption of sunlight to a certain extent, but it is easy to cause local excitonic quenching. Inorganic nanomaterials generally undergo organic modification and treatment, which results in poor compatibility of the material in the battery system and affects the efficiency of the battery. Based on the above statements, the present invention proposes a method for preparing a rare earth up-conversion nanodisk polymer solar cell.

Contents of the invention

The purpose of the present invention is to solve the shortcomings in the prior art, and propose a rare earth up-conversion nano-disc polymer solar cell preparation method.

A method for preparing a rare earth up-conversion nano-disc polymer solar cell, comprising the following steps:

Step 1: synthesis of nanoparticles with KGdF ₄ :Yb ³⁺ /Er ³⁺ disc structure;

(1) Dissolve 0.78mmol of GdCl ₃ .H2O, 0.20mmol of YbCl ₃ .H2O and 0.02mmol of ErCl ₃ .H2O in 30mL of ethylene glycol and dissolve them completely to obtain solution A;

(2) Weigh 0.28 g of polyvinylpyrrolidone with a molecular weight of 10000, add it to solution A, then add 1 mmol of KCl, and stir evenly at 80° C.;

(3) Weigh 0.50 g of glucose and add it into solution A, and stir to obtain solution 1;

(4) Dissolve 1 mmol of NH ₄ F in 10 mL of ethylene glycol, and stir at 80°C to obtain solution 2;

(5) Slowly add solution 1 dropwise to solution 2, fully stir, and mix uniformly to obtain solution 3;

(6) Transfer solution 3 into a polytetrafluoroethylene liner reactor, seal it, react at 200° C. for 4 hours, and then naturally cool to room temperature;

(7) After the reaction kettle is naturally cooled to room temperature, transfer the solution to a centrifuge tube, and use a centrifuge at 6000rpm/min to centrifuge for 5 minutes at room temperature, then pour out the upper layer of the centrifuge tube, add an appropriate amount of ethanol to clean, and clean Three times, dispersed in ethanol solution;

Step 2: Preparation of polymer solar cells for up-conversion KGdF ₄ :Yb ³⁺ /Er ³⁺ nanodisks;

(1) Clean the transparent substrate with the anode electrode sequentially with detergent, deionized water, acetone, deionized water and isoalcohol, and dry it with dry nitrogen after cleaning to form a clean conductive substrate;

(2) The above-mentioned conductive substrate is transferred to a plasma surface treatment instrument, and the conductive substrate is plasma-treated for 6 minutes under 25Pa pressure, oxygen and nitrogen environment, and then cooled to room temperature;

(3) ultrasonically disperse the KGdF ₄ :Yb ³⁺ /Er ³⁺ nano-disks prepared in step 2, and spin-coat on the conductive substrate by means of a homogenizer;

(4) form the conductive substrate with one layer of hole transport layer by the method of spin-coating the hole transport layer by a glue leveler;

(5) then form one layer of photoactive layer on the hole transport layer of step (4) by the method for spin-coating of glue homogenizer;

(6) The material of the electron buffer layer and the cathode electrode is spin-coated on the surface of the above-mentioned electrode by a homogenizer to obtain a polymer solar cell with rare earth co-doped KGdF ₄ nano-discs.

Preferably, the amount of glucose in the step 1 can be 0-1 g.

Preferably, the method of spin-coating with a homogenizer in the step 3 can be replaced by a method of vapor deposition or magnetron sputtering.

Preferably, the anode electrode in the step three is a transparent conductive metal oxide or a doped metal oxide, including indium tin oxide, fluorine-doped tin oxide and tin oxide, and the anode electrode is deposited by vapor phase deposition or magnetron sputtering method is formed.

Preferably, the transparent substrate in the third step is a hard substrate or a flexible substrate, wherein the hard substrate includes glass, quartz and metal.

Preferably, the hole transport layer in the step 3 is PEDOT:PSS polymer conductive polymer film or other metal oxide films with transmittance in the visible light wavelength range, wherein PEDOT is 3,4-ethylenedi A polymer of oxythiophene monomers, PSS is polystyrene sulfonate.

Preferably, the photoactive layer in the third step includes polythiophenes, poly(p-phenylene vinylene derivatives) and narrow bandgap conjugated donor polymer materials.

A method for preparing rare earth up-conversion nano-disc polymer solar cells proposed by the present invention, synthesizes KGdF ₄ :Yb ³⁺ /Er ³⁺ disc-shaped nanoparticles by controlling the conditions, and directly applies it to the conduction of polymer solar cells layer surface, the fluorescent emission range of KGdF ₄ :Yb ³⁺ /Er ³⁺ matches the absorption of the active layer of the polymer solar cell, this structure effectively improves the stability of the material, and can effectively improve the photoelectric conversion efficiency of the cell. The present invention Compared with the existing technology, discoid nanoparticles doped with rare earth ions are directly modified on the electrode surface, which increases the light absorption area, effectively reduces the recombination of photogenerated electrons and holes, and broadens the absorption range of sunlight. , compared with the battery without prepared particles, its open circuit voltage increased from 0.75V to 0.76V, the current density increased from 14.77mA·cm ^-2 to 15.69mA·cm ^-2 , and the solar energy conversion efficiency of the battery increased from 7.19% to 7.80%, an increase of about 9%. In addition, the filling factor is also slightly improved. The preparation process is simple and repeatable, and it is worth popularizing.

Description of drawings

Fig. 1 is an X-ray diffraction pattern of KGdF ₄ :Yb ³⁺ /Er ³⁺ prepared in the present invention.

Fig. 2 The present invention relates to the transmission electron microscope picture (a) and high resolution transmission electron microscope picture (b) of KGdF ₄ :Yb ³⁺ /Er ³⁺ .

Fig. 3 is a schematic diagram of the structure and principle of the polymer solar cell involved in the present invention, including 1 transparent substrate, 2 KGdF ₄ : Yb ³⁺ /Er ³⁺ modified anode electrode, 3 hole transport layer, 4 photoactive layer, 5 electron buffer layer , 6 cathode electrodes.

FIG. 4 is a graph of current density and voltage of the solar cell of the present invention and a reference polymer solar cell.

Fig. 5 is transmission electron micrographs of KGdF ₄ :Yb ³⁺ /Er ³⁺ with different amounts of glucose (a) 0g, (b) 0.15g and (c) 0.7g, respectively.

detailed description

The present invention will be further explained below in conjunction with specific embodiments.

Embodiment one

A method for preparing a rare earth up-conversion nanodisk polymer solar cell proposed by the present invention comprises the following steps:

Step 1: Synthesis of KGdF ₄ : Yb ³⁺ /Er ³⁺ nanoparticles with a disk-like structure (without adding glucose, the TEM picture of which is shown in Figure 5a);

(1) Dissolve 0.78mmol of GdCl ₃ .H2O, 0.20mmol of YbCl ₃ .H2O and 0.02mmol of ErCl ₃ .H2O in 30mL of ethylene glycol and dissolve them completely to obtain solution A;

(2) Weigh 0.28 g of polyvinylpyrrolidone with a molecular weight of 10,000, add it to (1), then add 1 mmol of KCl, and stir at 80° C. to obtain solution 1;

(3) Dissolve 1 mmol of NH ₄ F in 10 mL of ethylene glycol, and stir at 80°C to obtain solution 2;

(4) Slowly add solution 1 dropwise to solution 2, fully stir, and mix uniformly to obtain solution 3;

(5) Transfer the solution 3 into a polytetrafluoroethylene liner reactor, seal it, react at 200° C. for 4 hours, and then naturally cool to room temperature;

(6) After the reaction kettle is naturally cooled to room temperature, transfer the solution to a centrifuge tube, centrifuge at 6000rpm/min for 5 minutes at room temperature, then pour out the upper layer of the centrifuge tube, add an appropriate amount of ethanol to clean, and wash together Three times, dispersed in ethanol solution;

Step 2: Preparation of polymer solar cells of KGdF ₄ :Yb ³⁺ /Er ³⁺ nanodisks;

(1) Clean the transparent substrate with the anode electrode sequentially with detergent, deionized water, acetone, deionized water and isoalcohol, and dry it with dry nitrogen after cleaning to form a clean conductive substrate;

(2) The above-mentioned conductive substrate is transferred to a plasma surface treatment instrument, and the conductive substrate is plasma-treated for 6 minutes under 25Pa pressure, oxygen and nitrogen environment, and then cooled to room temperature;

(3) ultrasonically disperse the nanodisk KGdF ₄ :Yb ³⁺ /Er ³⁺ prepared in step 2, and spin-coat it on the conductive substrate by means of a homogenizer;

(4) form the conductive substrate with one layer of hole transport layer by the method of spin-coating the hole transport layer by a glue leveler;

(5) then form one layer of photoactive layer on the hole transport layer of step (4) by the method for spin-coating of glue homogenizer;

(6) The material of the electron buffer layer and the cathode electrode is spin-coated on the surface of the above-mentioned electrode by a homogenizer to obtain a polymer solar cell with rare earth co-doped KGdF ₄ nano-discs.

Embodiment two

A method for preparing a rare earth up-conversion nanodisk polymer solar cell proposed by the present invention comprises the following steps:

Step 1: Synthesis of KGdF ₄ :Yb ³⁺ /Er ³⁺ nanoparticles with a disk-like structure (the amount of glucose added is 0.15 g, and its transmission electron microscope picture is shown in Figure 5b);

(1) Dissolve 0.78mmol of GdCl ₃ .H2O, 0.20mmol of YbCl ₃ .H2O and 0.02mmol of ErCl ₃ .H2O in 30mL of ethylene glycol and dissolve them completely to obtain solution A;

(2) Weigh 0.28 g of polyvinylpyrrolidone with a molecular weight of 10000, add it to solution A, then add 1 mmol of KCl, and stir evenly at 80° C.;

(3) Weigh 0.15g of glucose and add it into solution A, and stir to obtain solution 1;

(4) Dissolve 1 mmol of NH ₄ F in 10 mL of ethylene glycol, and stir at 80°C to obtain solution 2;

(5) Slowly add solution 1 dropwise to solution 2, fully stir, and mix uniformly to obtain solution 3;

(6) Transfer solution 3 into a polytetrafluoroethylene liner reactor, seal it, react at 200° C. for 4 hours, and then naturally cool to room temperature;

(7) After the reaction kettle is naturally cooled to room temperature, transfer the solution to a centrifuge tube, and use a centrifuge at 6000rpm/min to centrifuge for 5 minutes at room temperature, then pour out the upper layer of the centrifuge tube, add an appropriate amount of ethanol to clean, and clean Three times, dispersed in ethanol solution;

Step 2: Preparation of polymer solar cells of KGdF ₄ :Yb ³⁺ /Er ³⁺ nanodisks;

(1) Clean the transparent substrate with the anode electrode sequentially with detergent, deionized water, acetone, deionized water and isoalcohol, and dry it with dry nitrogen after cleaning to form a clean conductive substrate;

(2) The above-mentioned conductive substrate is transferred to a plasma surface treatment instrument, and the conductive substrate is plasma-treated for 6 minutes under 25Pa pressure, oxygen and nitrogen environment, and then cooled to room temperature;

(3) Ultrasonic dispersion of KGdF ₄ :Yb ³⁺ /Er ³⁺ prepared in step 2, and spin-coating on the conductive substrate by means of a homogenizer;

(4) form the conductive substrate with one layer of hole transport layer by the method of spin-coating the hole transport layer by a glue leveler;

(5) then form one layer of photoactive layer on the hole transport layer of step (4) by the method for spin-coating of glue homogenizer;

(6) The material of the electron buffer layer and the cathode electrode is spin-coated on the surface of the above-mentioned electrode by a homogenizer to obtain a polymer solar cell with rare earth co-doped KGdF ₄ nano-discs.

Embodiment three

A method for preparing a rare earth up-conversion nanodisk polymer solar cell proposed by the present invention comprises the following steps:

Step 1: Synthesis of KGdF ₄ : Yb ³⁺ /Er ³⁺ nanoparticles with a disk-like structure (the amount of glucose added is 0.70 g, and its transmission electron microscope picture is shown in Figure 5c);

(1) Dissolve 0.78mmol of GdCl ₃ .H2O, 0.20mmol of YbCl ₃ .H2O and 0.02mmol of ErCl ₃ .H2O in 30mL of ethylene glycol and dissolve them completely to obtain solution A;

(2) Weigh 0.28 g of polyvinylpyrrolidone with a molecular weight of 10000, add it to solution A, then add 1 mmol of KCl, and stir evenly at 80° C.;

(3) Weigh 0.70 g of glucose and add it into solution A, and stir to obtain solution 1;

(4) Dissolve 1 mmol of NH ₄ F in 10 mL of ethylene glycol, and stir at 80°C to obtain solution 2;

(5) Slowly add solution 1 dropwise to solution 2, fully stir, and mix uniformly to obtain solution 3;

(6) Transfer solution 3 into a polytetrafluoroethylene liner reactor, seal it, react at 200° C. for 4 hours, and then naturally cool to room temperature;

(7) After the reaction kettle is naturally cooled to room temperature, transfer the solution to a centrifuge tube, and use a centrifuge at 6000rpm/min to centrifuge for 5 minutes at room temperature, then pour out the upper layer of the centrifuge tube, add an appropriate amount of ethanol to clean, and clean Three times, dispersed in ethanol solution;

Step 2: Preparation of polymer solar cells of KGdF ₄ :Yb ³⁺ /Er ³⁺ nanodisks;

(1) Clean the transparent substrate with the anode electrode sequentially with detergent, deionized water, acetone, deionized water and isoalcohol, and dry it with dry nitrogen after cleaning to form a clean conductive substrate;

(2) The above-mentioned conductive substrate is transferred to a plasma surface treatment instrument, and the conductive substrate is plasma-treated for 6 minutes under 25Pa pressure, oxygen and nitrogen environment, and then cooled to room temperature;

(3) Ultrasonic dispersion of KGdF ₄ :Yb ³⁺ /Er ³⁺ prepared in step 2, and spin-coating on the conductive substrate by means of a homogenizer;

(4) form the conductive substrate with one layer of hole transport layer by the method of spin-coating the hole transport layer by a glue leveler;

(5) then form one layer of photoactive layer on the hole transport layer of step (4) by the method for spin-coating of glue homogenizer;

(6) The material of the electron buffer layer and the cathode electrode is spin-coated on the surface of the above-mentioned electrode by a homogenizer to obtain a polymer solar cell with rare earth co-doped KGdF ₄ nano-discs.

A method for preparing rare earth up-conversion nano-disc polymer solar cells proposed by the present invention, synthesizes KGdF ₄ :Yb ³⁺ /Er ³⁺ disc-shaped nanoparticles by controlling the conditions, and directly applies it to the conduction of polymer solar cells On the surface of the layer, the fluorescent emission range of KGdF ₄ :Yb ³⁺ /Er ³⁺ matches the absorption of the active layer of the polymer solar cell, effectively improving the stability and stability of the material, and effectively improving the photoelectric conversion efficiency of the cell. The present invention Compared with the existing technology, the upconversion discoid nanoparticles are directly modified on the surface of the electrode, which increases the light absorption area, effectively reduces the recombination of photogenerated electrons and holes, and broadens the absorption range of sunlight. The open circuit voltage of the battery without prepared particles increased from 0.75V to 0.76V, the current density increased from 14.77mA·cm ^-2 to 15.69mA·cm ^-2 , and the solar energy conversion efficiency of the battery increased from 7.19% to 7.80%. Increased by about 9%, in addition, the filling factor is also slightly improved, the preparation process is simple, strong repeatability, it is worth popularizing.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (7)

1. a kind of rare earth upconversion nano disk polymer solar battery preparation method is it is characterised in that comprise the following steps：

Step one：KGdF₄:Yb³⁺/Er³⁺The synthesis of the nanometer plate of disk-like structure；

(1) by the GdCl of 0.78mmol₃.H2O, the YbCl of 0.20mmol₃.H2O the ErCl with 0.02mmol₃.H2O it is dissolved in So as to be completely dissolved in 30mL ethylene glycol, obtain solution A；

(2) weigh the polyvinylpyrrolidone 0.28g that molecular weight is 10000, add in solution A, be subsequently adding the KCl of 1mmol, Stir at 80 DEG C；

(3) weigh 0.50g glucose to add in solution A, stir to obtain solution 1；

(4) by the NH of 1mmol₄F is dissolved in the ethylene glycol of 10mL, and stir to obtain at 80 DEG C solution 2；

(5) solution 1 is slowly added drop-wise in solution 2, is sufficiently stirred for, mix to obtain solution 3；

(6) solution 3 is proceeded in polytetrafluoroethylliner liner reactor, sealing, react 4 hours at 200 DEG C, then natural cooling To room temperature；

(7) after reactor naturally cools to room temperature, transfer the solution in centrifuge tube, use centrifuge 6000rpm/min The supernatant liquid of centrifuge tube is poured out by centrifugation 5 minutes afterwards under room temperature, adds ethanol in proper amount cleaning, cleans three times altogether, point It is dispersed in ethanol solution；

Step 2：KGdF₄:Yb³⁺/Er³⁺The polymer solar battery preparation of nanometer plate；

(1) transparent substrates with anode electrode are used successively washing agent, deionized water, acetone, deionized water and different alcohol ultrasonic Cleaning, is dried up with dry nitrogen after cleaning, forms clean conductive substrates；

(2) above-mentioned conductive substrates are proceeded to plasma surface treatment instrument, to leading under 25Pa air pressure, oxygen and nitrogen environment Electric substrate plasma treatment was cooled to room temperature after 6 minutes；

(3) step 2 is prepared KGdF₄:Yb³⁺/Er³⁺Nanometer plate ultrasonic disperse, by the method for sol evenning machine spin coating in conductive substrates On；

(4) hole transmission layer is formed the conductive substrates with one layer of hole transmission layer by the method for sol evenning machine spin coating；

(5) method then passing through sol evenning machine spin coating forms one layer of photoactive layer on the hole transmission layer of step (4)；

(6) material of electron buffer layer and cathode electrode is passed through the method for sol evenning machine spin coating on the surface of above-mentioned electrode, obtain Rare earth codope KGdF₄The polymer solar battery of nanometer plate.

2. a kind of rare earth according to claim 1 is co-doped with nanometer plate polymer solar battery preparation method, and its feature exists In in described step one, the amount of glucose can be 0～1g.

3. a kind of rare earth according to claim 1 is co-doped with nanometer plate polymer solar battery preparation method, and its feature exists In in described step 3, the method for sol evenning machine spin coating could alternatively be vapour deposition or the method for magnetron sputtering.

4. a kind of rare earth according to claim 1 is co-doped with nanometer plate polymer solar battery preparation method, and its feature exists In the anode electrode in described step 3 is the metal oxide of electrically conducting transparent or the metal oxide having doping, including oxidation Indium tin, fluorine doped tin oxide and tin oxide, anode electrode is formed by the method for vapour deposition or magnetron sputtering.

5. a kind of rare earth according to claim 1 is co-doped with nanometer plate polymer solar battery preparation method, and its feature exists It is hard substrate or flexible substrates in, transparent substrates in described step 3, wherein hard substrate includes glass, quartzy and golden Belong to.

6. a kind of rare earth according to claim 1 is co-doped with nanometer plate polymer solar battery preparation method, and its feature exists In the hole transmission layer in described step 3 is PEDOT:PSS conducting polymer thin polymer film or other in visible wavelength In the range of have the metal-oxide film of transmitance, wherein PEDOT is the polymer of 3,4-ethylene dioxythiophene monomer, and PSS is Poly styrene sulfonate.

7. a kind of rare earth according to claim 1 is co-doped with nanometer plate polymer solar battery preparation method, and its feature exists In the photoactive layer in described step 3 includes polythiophene class, gathers to phenylethylene derivative and the polymerization of narrowband gap conjugated donor Thing material.