CN101692481B - Solar cell having integrated structure of plane-bulk heterojunction and preparation method thereof - Google Patents

Abstract

The invention discloses a plane-bulk heterojunction integrated solar cell and a preparation method thereof, which belong to the technical field of solar cells. The solar cell of the present invention includes a glass substrate, an anode, an anode modification layer, a photoelectric active layer, and a cathode stacked in sequence, and is characterized in that a conjugated polymer electron layer with a thickness of 2-30 nm is arranged between the anode modification layer and the photoelectric active layer. Donor material layer, prepared by spin coating or inkjet printing method of conjugated polymer electron donor material coating and conjugated polymer electron donor material and semiconductor nanocrystalline electron acceptor material mixed photoelectric active layer . The invention combines the advantages of planar structure and body heterojunction structure battery, and has many advantages such as simple manufacturing process, easy control, good reproducibility, solution processing, etc. The energy conversion efficiency has been significantly improved.

Description

A kind of plane-bulk heterojunction integrated structure solar cell and its preparation method

technical field

The invention belongs to the technical field of solar cells, in particular to a solar cell with a plane-bulk heterojunction integrated structure and a preparation method thereof.

Background technique

In order to maximize the use of the entire spectral range of sunlight, the structure of organic/inorganic hybrid solar cells sensitized with conjugated polymers using narrow-bandgap semiconductor nanocrystalline quantum dots (such as CdSe, PbS, PbSe) has recently been proposed, The structure shows enhanced light absorption performance in the long wavelength direction greater than 650nm (1: S.A.Mcdonald, G.Konstantatos, S.Zhang, P.W.Cyr, E.J.D.Klem, L.Levina, and E.H.Sargent, Nature Mater.2005, 4, 138; 2: D. Cui, J. Xu, T. Zhu, G. Paradee, and S. Ashok, Appl. Phys. Lett. 2006, 88, 183111). At the same time, organic/inorganic hybrid solar cells have attracted widespread attention due to their advantages such as simple preparation process, light weight, low cost, and easy preparation of large-area flexible devices (1: W.U.Huynh, J.J.Dittmer, and A.P. Alivisotos, Science 2002, 295 , 2425; 2: X.Jiang, R.D.Schaller, S.B.Lee, J.M.Pietryga, V.I.Klimov, and A.A.Zakhidov, J.Mater.Res.2007, 22, 2204; 3: D.Qi, M.Fischbein, M.Drndic , and S.Selmic, Appl.Phys.Lett.2005, 86, 093103; 4: S.Kumar and G.D.Scholes, Microchim.Acta 2008, 160, 315; 5: G.Konstantatos, I.Howard, A.Fischer, S. Hoogland, J. Clifford, E. Klem, L. Levina, and E. H. Sargent, Nature 2006, 442, 180). Almost all organic/inorganic hybrid solar cell structures are applied to the bulk heterojunction structure, because the photogenerated excitons in the conjugated polymer in the bulk heterojunction structure can be effectively separated at the donor-acceptor interface. High photogenerated carrier efficiency. However, studies have shown that in bulk heterojunctions of conjugated polymer/semiconductor nanocrystal blends, holes and electrons migrate less before recombination than in pure polymers (1: W.U.Huynh, J.J. Dittmer, N. Teclemariam, D.J. Milliron, A.P. Alivisatos, and K.W.J. Bamham, Phys. Rev. B 2003, 67, 115326). If the planar heterojunction and bulk heterojunction can be integrated by solution processing, it will not only improve the carrier transport and collection efficiency, but also make full use of the full spectrum of sunlight.

Contents of the invention

The object of the present invention is to provide a planar-bulk heterojunction integrated solar cell and a preparation method thereof.

A planar-bulk heterojunction integrated structure solar cell, comprising a glass substrate 1, an anode 2, an anode modification layer 3, a photoelectric active layer 4, and a cathode 5 stacked in sequence, characterized in that the anode modification layer 3 and the photoelectric active layer A conjugated polymer electron donor material layer 6 is provided between the 4, and the thickness of the conjugated polymer electron donor material layer is 2-30 nm.

The conjugated polymer electron donor material is selected from: polyparaphenylene vinylene, polyarylene vinylene, polyparaphenylene, polyarylene, polythiophene, polyquinone morphines.

The photoelectric active layer 4 is a photoactive layer formed by mixing a conjugated polymer electron donor material and a semiconductor nanocrystalline electron acceptor material, wherein the conjugated polymer electron donor material is selected from the group consisting of: poly( Phenylvinylene), poly(arylenevinylene), poly(p-phenylene), poly(arylene), polythiophene, polyquinoline, the semiconductor nanocrystalline electronics The acceptor material is selected from the group of III-V, II-VI and IV-VI compound semiconductors.

The cathode includes alkali metal, alkaline earth metal, aluminum, silver, copper, or an alloy composed of the above metals.

A method for preparing a planar-bulk heterojunction integrated solar cell, characterized in that the steps of the method are as follows:

(1) ultrasonically clean the transparent conductive glass sputtered with ITO anode, and then treat the substrate surface with ozone;

(2) Spin coat 30 nanometers of thick PEDOT:PSS as the anode modification film again, dry;

(3) dissolving the conjugated polymer electron donor material in a solvent, coating it on the above-mentioned anode-modified substrate by spin coating or inkjet printing, and drying at 80-250°C for 10-48min, Cool naturally to room temperature to form a conjugated polymer electron donor material layer with a thickness of 2-30nm;

(4) The conjugated polymer electron donor material is mixed with the semiconductor nanocrystalline electron acceptor material and the solvent, and the resulting mixed solution is directly coated on the conjugated polymer electron donor by spin coating or inkjet printing. On the material layer, after drying, it is naturally cooled to room temperature to form a photoelectric active layer;

(5) Vacuum-evaporating metal directly on the photoelectric active layer through a mask to form a cathode to obtain a conjugated polymer/semiconductor nanocrystal planar-bulk heterojunction integrated solar cell.

In the step (3), the rotation speed is 1000-3000 revolutions per minute when the coating is rotated.

The beneficial effects of the present invention are:

1. This method can directly coat the conjugated polymer/semiconductor nanocrystal optoelectronic active layer on the lower conjugated polymer by spin coating or inkjet printing;

2. There is no damage to the lower conjugated polymer when spin-coating or inkjet printing the upper conjugated polymer/semiconductor nanocrystal optoelectronic active layer;

3. The method has simple process, low cost, easy control of film thickness, and is suitable for large-scale industrial production;

4. The conjugated polymer layer in this method needs to be dried at a higher temperature, the drying temperature can be from 80 to 250 degrees Celsius, and the drying time can be from 10 minutes to 48 hours;

5. The conjugated polymer/semiconductor nanocrystalline solar cell prepared with this integrated structure has a photoelectric energy conversion efficiency superior to that of traditional bulk heterojunction structure devices.

Description of drawings

Fig. 1 is the device structure of solar cell, wherein, (a) is bulk heterojunction solar cell, (b) is the plane-bulk heterojunction integrated structure conjugated polymer/semiconductor nanocrystalline solar cell of the present invention;

Fig. 2 is a cross-sectional scanning electron microscope diagram of a solar cell, wherein (a) is a bulk heterojunction solar cell, and (b) is a planar-bulk heterojunction integrated structure conjugated polymer/semiconductor nanocrystalline solar cell of the present invention;

Fig. 3 is the bulk heterojunction and planar-bulk heterojunction integrated structure (1000rpm prepares P3HT) solar cell prepared by embodiment 1 and the bulk heterojunction structure solar cell prepared by comparative example under the 532nm illumination of 100mW/ ^cm IV curve;

Fig. 4 is the bulk heterojunction and planar-bulk heterojunction integrated structure (1000rpm prepares P3HT) solar cell prepared by embodiment 1 and the bulk heterojunction structure solar cell prepared by comparative example under the 808nm illumination of 100mW/ ^cm IV curve;

Fig. 5 is the bulk heterojunction and planar-bulk heterojunction integrated structure (2000rpm prepares P3HT) solar cell prepared in embodiment 2 and the ^bulk heterojunction structure solar cell prepared in comparative example under the 532nm illumination of 100mW/cm IV curve;

Fig. 6 is the bulk heterojunction and planar-bulk heterojunction integrated structure (2000rpm prepares P3HT) solar cell prepared by embodiment 2 and the bulk heterojunction ^structure solar cell prepared by comparative example under the 808nm illumination of 100mW/cm IV curve;

Fig. 7 is the bulk heterojunction and planar-bulk heterojunction integrated structure (3000rpm prepares P3HT) solar cell prepared in embodiment 3 and the bulk heterojunction structure solar cell prepared in comparative example under the 532nm illumination of 100mW/ ^cm IV curve;

Fig. 8 is the bulk heterojunction and planar-bulk heterojunction integrated structure (3000rpm prepares P3HT) solar cell prepared in embodiment 3 and the bulk heterojunction structure solar cell prepared in comparative example under ^the 808nm illumination of 100mW/cm IV curve;

Symbols in the figure: 1 - glass substrate; 2 - anode; 3 - anode modification layer; 4 - photoelectric active layer; 5 - cathode; 6 conjugated polymer electron donor material layer.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing:

The bulk heterojunction solar cell is shown in Figure 1(a), which includes a glass substrate 1, anode 2, anode modification layer 3, photoelectric active layer 4, and cathode 5 stacked in sequence. The planar-bulk heterojunction integration of the present invention Structural solar cells, as shown in Figure 1(b), include a glass substrate 1, an anode 2, an anode modification layer 3, a photoelectric active layer 4, and a cathode 5 stacked in sequence, and between the anode modification layer 3 and the photoelectric active layer 4 There is a conjugated polymer electron donor material layer 6 between them, and the thickness of the conjugated polymer electron donor material layer is 2-30nm.

Comparative Example Conventional Bulk Heterojunction Solar Cells

The transparent conductive glass sputtered with ITO (anode) was ultrasonically cleaned with detergent, deionized water, acetone, and isopropanol in sequence, and then the surface of the substrate was treated with ozone, and then spin-coated with 30 nm thick PEDOT:PSS as Anodically modified film, dried at 150°C for 10 minutes, the mixed solution obtained by dissolving P3HT and PbSe in chlorobenzene solution (containing 10 mg of P3HT and 50 mg of PbSe per milliliter of chlorobenzene solution) at a speed of 1000 revolutions per minute (rpm) Spin-coat directly on the above-mentioned anode-modified substrate, then dry at 80°C for 30 minutes, and naturally cool to room temperature to form a photoelectric active layer with a thickness of 50nm; finally, vacuum vapor deposition at 5×10 ^-5 Pa through a mask 150 nanometers of aluminum is used as the cathode to obtain a bulk heterojunction solar cell, and the device structure is shown in Figure 1(a).

The bulk heterojunction structure solar cells that are compared in the following examples are all solar cells prepared in this comparative example. As can be seen from the figure, the traditional bulk heterojunction structure solar cells have Under light irradiation, the open circuit voltage is 0.28 volts, the short-circuit current is 0.9 mA per square centimeter, the fill factor is 0.39, and the conversion efficiency is 0.1%. It is 1.1 mA per square centimeter, the fill factor is 0.36, and the conversion efficiency is 0.1%.

Example 1

The transparent conductive glass sputtered with ITO (anode) was ultrasonically cleaned with detergent, deionized water, acetone, and isopropanol in sequence, and then the surface of the substrate was treated with ozone, and then spin-coated with 30 nm thick PEDOT:PSS as Anode modification film, 150 ℃ of drying 10 minutes, the P3HT chlorobenzene solution of 10 milligrams per milliliter (containing 10 milligrams of P3HT in every milliliter of chlorobenzene solution) is directly spin-coated under the rotating speed of 1000 revolutions per minute (rpm) on above-mentioned anode modified substrate, then dried at 150°C for 30 minutes, and naturally cooled to room temperature to form a conjugated polymer electron donor material layer with a thickness of 20nm. The mixed solution obtained by dissolving P3HT and PbSe in chlorobenzene solution (per milliliter of chlorobenzene The solution containing 10 mg P3HT, containing 50 mg PbSe) was directly spin-coated on the P3HT film at a speed of 1000 revolutions per minute (rpm), then dried at 80 °C for 30 minutes, and naturally cooled to room temperature to form a photoactive film with a thickness of 50 nm. layer; finally, 150 nanometers of aluminum was vacuum-deposited through a mask at 5×10 ^-5 Pa as a cathode to obtain a conjugated polymer/semiconductor nanocrystal planar-bulk heterojunction integrated solar cell, and the device structure is shown in Figure 1 (b) shown.

The SEM photos of the cross-section shown in Figure 2 clearly reflect that the upper P3HT:PbSe mixed film did not cause any damage to the lower P3HT.

Fig. 3, Fig. 4 have shown the current-voltage curve under the 532nm and 808nm irradiation of 100 milliwatts per square centimeter of the plane-bulk heterojunction integrated structure solar cell that the present embodiment makes, as can be seen from the figure, The planar-bulk heterojunction integrated structure solar cell prepared in this example has an open circuit voltage of 0.39 volts, a short-circuit current of 0.94 milliamps per square centimeter, and a fill factor of 0.35 under the irradiation of 532 nm light at 100 milliwatts per square centimeter. The efficiency is 0.13%, and the device performance is 33% higher than the conversion efficiency of the traditional bulk heterojunction structure; under the irradiation of 808nm light at 100 mW/cm2, the open circuit voltage is 0.36 volts, and the short circuit current is 1.36 mA/cm2. The factor is 0.33, the conversion efficiency is 0.16%, and the device performance is 60% higher than the conversion efficiency of the traditional bulk heterojunction structure.

Example 2

The transparent conductive glass sputtered with ITO (anode) was ultrasonically cleaned with detergent, deionized water, acetone, and isopropanol in sequence, and then the surface of the substrate was treated with ozone, and then spin-coated with 30 nm thick PEDOT:PSS as Anode modification film, 150 ℃ of drying 10 minutes, the P3HT chlorobenzene solution of 10 milligrams per milliliter (containing 10 milligrams of P3HT in every milliliter of chlorobenzene solution) is directly spin-coated under the rotating speed of 2000 revolutions per minute (rpm) on above-mentioned via anode modified substrate, then dried at 150°C for 30 minutes, cooled naturally to room temperature, and formed a conjugated polymer electron donor material layer with a thickness of 15nm. The mixed solution obtained by dissolving P3HT and PbSe in chlorobenzene solution (per milliliter of chlorobenzene The solution containing 10 mg P3HT, containing 50 mg PbSe) was directly spin-coated on the P3HT film at a speed of 1000 revolutions per minute (rpm), then dried at 80 °C for 30 minutes, and naturally cooled to room temperature to form a photoactive film with a thickness of 50 nm. layer; finally, 150 nanometers of aluminum was vacuum-deposited through a mask at 5×10 ^-5 Pa as a cathode to obtain a conjugated polymer/semiconductor nanocrystal planar-bulk heterojunction integrated solar cell, and the device structure is shown in Figure 1 (b) shown.

Fig. 5 and Fig. 6 show the current-voltage curves of the plane-bulk heterojunction integrated structure solar cell prepared in this embodiment under the irradiation of 532nm and 808nm at 100 milliwatts per square centimeter, as can be seen from the figure, The planar-bulk heterojunction integrated structure solar cell prepared in this embodiment has an open circuit voltage of 0.35 volts, a short circuit current of 1.35 milliamperes per square centimeter, and a fill factor of 0.44 under the irradiation of 532 nm light at 100 milliwatts per square centimeter. The efficiency is 0.21%, and the device performance is 110% higher than the conversion efficiency of the traditional bulk heterojunction structure; under the irradiation of 808nm light at 100 mW/cm2, the open circuit voltage is 0.38 volts, and the short circuit current is 1.73 mA/cm2. The factor is 0.40, the conversion efficiency is 0.26%, and the device performance is 160% higher than the conversion efficiency of the traditional bulk heterojunction structure.

Example 3

The transparent conductive glass sputtered with ITO (anode) was ultrasonically cleaned with detergent, deionized water, acetone, and isopropanol in sequence, and then the surface of the substrate was treated with ozone, and then spin-coated with 30 nm thick PEDOT:PSS as Anode modification film, 150 ℃ of drying 10 minutes, the P3HT chlorobenzene solution of 10 milligrams per milliliter (containing 10 milligrams of P3HT in every milliliter of chlorobenzene solution) is directly spin-coated on above-mentioned through anode under the rotating speed of 3000 revolutions per minute (rpm). modified substrate, then dried at 150°C for 30 minutes, and cooled naturally to room temperature to form a conjugated polymer electron donor material layer with a thickness of 10nm. The mixed solution obtained by dissolving P3HT and PbSe in chlorobenzene solution (per milliliter of chlorobenzene The solution containing 10 mg P3HT, containing 50 mg PbSe) was directly spin-coated on the P3HT film at a speed of 1000 revolutions per minute (rpm), then dried at 80 °C for 30 minutes, and naturally cooled to room temperature to form a photoactive film with a thickness of 50 nm. layer; finally, 150 nanometers of aluminum was vacuum-deposited through a mask at 5×10 ^-5 Pa as a cathode to obtain a conjugated polymer/semiconductor nanocrystal planar-bulk heterojunction integrated solar cell, and the device structure is shown in Figure 1 (b) shown.

Fig. 7 and Fig. 8 show the current-voltage curves of the plane-bulk heterojunction integrated structure solar cell prepared in this embodiment under the irradiation of 532nm and 808nm at 100 milliwatts per square centimeter, as can be seen from the figure, The planar-bulk heterojunction integrated structure solar cell prepared in this embodiment has an open circuit voltage of 0.38 volts, a short circuit current of 1.12 milliamperes per square centimeter, and a fill factor of 0.38 under the irradiation of 100 milliwatts per square centimeter of 532 nm light. The efficiency is 0.16%, and the device performance is 60% higher than the conversion efficiency of the traditional bulk heterojunction structure; under the irradiation of 808nm light at 100 mW/cm2, the open circuit voltage is 0.36 volts, and the short circuit current is 1.57 mA/cm2. The factor is 0.36, the conversion efficiency is 0.20%, and the device performance is 100% higher than the conversion efficiency of the traditional bulk heterojunction structure.

The above examples show that the planar-bulk heterojunction integrated structure can effectively improve the performance of the device. This structure not only increases the open circuit voltage and short circuit current, but also improves the fill factor, thereby increasing the photoelectric conversion efficiency of the solar cell. Its low cost, simple process and its excellent performance make it have great application prospects in industry.

Claims (5)

1. A planar-bulk heterojunction integrated structure solar cell, comprising a glass substrate (1), an anode (2), an anode modification layer (3), a photoelectric active layer (4), and a cathode (5) stacked in sequence, It is characterized in that a conjugated polymer electron donor material layer (6) is provided between the anode modification layer (3) and the photoelectric active layer (4), and the thickness of the conjugated polymer electron donor material layer is 2-30nm , the conjugated polymer electron donor material is selected from: poly (p-phenylene vinylene) class, poly (arylene vinylene) class, poly (p-phenylene) class, poly (arylene ) class, polythiophene class, polyquinoline class. 2. A kind of plane-bulk heterojunction integrated structure solar cell according to claim 1, characterized in that said photoelectric active layer (4) is a conjugated polymer electron donor material and a semiconductor nanocrystal electron acceptor material A mixed photoelectric active layer, wherein the conjugated polymer electron donor material is selected from the group consisting of poly(p-phenylene vinylene), poly(arylene vinylene), poly(p-phenylene base) class, poly(arylene) class, polythiophene class, polyquinoline class, the semiconductor nanocrystalline electron acceptor material is from the group of III-V group, II-VI group and IV-VI group compound semiconductor selected from. 3 . A planar-bulk heterojunction integrated solar cell according to claim 1 , wherein the cathode comprises alkali metal, alkaline earth metal, aluminum, silver, copper, or an alloy composed of the above metals. 4. A method for preparing a planar-bulk heterojunction integrated structure solar cell, characterized in that the steps of the method are as follows: (1) ultrasonically clean the transparent conductive glass sputtered with ITO anode, and then treat the substrate surface with ozone; (2) Spin coat 30 nanometers of thick PEDOT:PSS as the anode modification film again, dry; (3) dissolving the conjugated polymer electron donor material in a solvent, coating it on the above-mentioned anode-modified substrate by spin coating or inkjet printing, and drying at 80-250°C for 10-48min, Cool naturally to room temperature to form a conjugated polymer electron donor material layer with a thickness of 2-30nm, wherein the conjugated polymer electron donor material is selected from: poly(p-phenylene vinylene), poly(arylene vinylene), poly(p-phenylene), poly(arylene), polythiophene, polyquinoline; (4) The conjugated polymer electron donor material is mixed with the semiconductor nanocrystalline electron acceptor material and the solvent, and the resulting mixed solution is directly coated on the conjugated polymer electron donor by spin coating or inkjet printing. On the material layer, after drying, it is naturally cooled to room temperature to form a photoelectric active layer; (5) Vacuum-evaporating metal directly on the photoelectric active layer through a mask to form a cathode to obtain a conjugated polymer/semiconductor nanocrystal planar-bulk heterojunction integrated solar cell. 5 . The method for preparing a planar-bulk heterojunction integrated structure solar cell according to claim 4 , characterized in that in the step (3), the rotating speed of the film coating is 1000-3000 rpm. 6 .

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