CN103219413A - A kind of graphene radial heterojunction solar cell and preparation method thereof - Google Patents

Abstract

The invention discloses a graphene radial heterojunction solar cell and a preparation method thereof, wherein the solar cell comprises: the device comprises a monocrystalline silicon substrate and p-type or n-type silicon nano-pillars formed on the monocrystalline silicon substrate; a passivation film, an amorphous silicon film inverse to the silicon nano-pillars, graphene and a TCO film are sequentially formed on the monocrystalline silicon substrate and the p-type or n-type silicon nano-pillars; a metal gate electrode fabricated on the TCO film; and a back electrode formed on the back surface of the single crystal silicon substrate. The invention integrates the advantages of the radial junction battery and the heterojunction battery, indirectly reduces the production cost by utilizing the high efficiency and low temperature process of the heterojunction battery, effectively improves the absorption and utilization of light by the radial junction, improves the collection efficiency of photon-generated carriers, thereby effectively improving the efficiency of the battery, and simultaneously utilizes the low temperature process of the heterojunction, has simple preparation process and good temperature stability, and is suitable for large-scale popularization and application.

Description

A kind of graphene radial heterojunction solar cell and preparation method thereof

technical field

The invention relates to the technical field of solar cells, in particular to a graphene radial heterojunction solar cell and a preparation method thereof.

Background technique

As a renewable energy source, solar energy is considered to be a new type of energy that can effectively replace fossil fuels. At the same time, the global demand for solar energy is increasing year by year. Solar cells are an effective photoelectric conversion device, and are considered to be one of the most promising new technologies that can effectively protect the environment and effectively utilize clean energy. The efficiency and production cost of solar cells are two key factors limiting the development of solar cells. Therefore, in order to improve the efficiency of solar cells and reduce their manufacturing costs, various solar cell technologies and new structures have emerged in recent years. As a high-efficiency solar cell, heterojunction solar cells are expected to become the leading direction of solar cell industrialization in the future, while radial junction solar cells, as a new type of structure, have great development prospects. Solar cells have a wide range of applications.

Heterojunction solar cell is a high-efficiency solar cell created by Sanyo Corporation of Japan. According to the literature [Kinoshita, T.; Fujishima, D.; Yano, A. over23%. The 26thEuropean Photovoltaic Solar Energy Conference and Exhibition, Hamburg, Germany, 2011: 871-874] reported that its efficiency has reached 23.7%. Heterojunction solar cells take advantage of thin-film technology in the manufacturing process, combining the characteristics of amorphous silicon and crystalline silicon materials. The biggest advantage of this solar cell is the low-temperature process, which has lower requirements for silicon substrates and is conducive to The thinning of the silicon substrate effectively saves the production cost of solar cells, high stability, and the performance of the cells will not decay as the temperature rises, and there will be no phenomenon of degradation due to light similar to amorphous silicon solar cells. Moreover, the preparation process is simple, and at the same time, the low-temperature process is not only beneficial to energy saving, but also can optimize device characteristics and avoid performance degradation that may occur during high-temperature treatment.

The absorption of light in radial junction solar cells occurs in the axial direction, which can effectively improve the utilization of light. At the same time, the separation of carriers occurs in the radial direction, which reduces the transport distance, reduces the recombination of electrons and holes, and effectively improves the current carrying capacity. The collection efficiency of electrons can significantly improve the short-circuit current and conversion efficiency of solar cells.

Graphene is a newly developed material with good light transmission and electrical conductivity. It has high-speed electron mobility at room temperature, up to 1.5×10 ⁴ cm ² ·V ^-1 ·s ^-1 , literature [Becerril , HA; Mao, J.; Liu, ZF; Stoltenberg, RM; Bao, ZN; Chen, YSEvaluation ofSolution-Processed Reduced Graphene Oxide Films as Transparent Conductors. The author and others spin-coated graphene oxide on the surface of quartz and subjected it to thermal reduction treatment, its electrical conductivity was 10 ² S·cm-1, and the light transmittance could reach 80% in the wavelength range of 400-1800nm. It shows that the material has good light transmission and conductivity, so it has great potential to be applied to solar cells, and can be used to replace ITO as a transparent conductive oxide film.

Accordingly, the present invention designs a graphene radial heterojunction solar cell, which fully combines the advantages of heterojunction and radial junction solar cells, improves carrier collection efficiency and utilizes heterojunction interface The optimized performance of graphene reduces the recombination effect, effectively improves the conversion efficiency of solar cells, indirectly reduces the production cost of solar cells, and uses the light-transmitting conductivity of graphene to improve the collection efficiency of short-circuit current, and the manufacturing process temperature of the cell is low. , using the advantages of the thin film manufacturing process and giving full play to the advantages of the performance of crystalline silicon and amorphous silicon materials, it is suitable for large-scale promotion.

Contents of the invention

(1) Technical problems to be solved

In view of this, the present invention combines the advantages of heterojunction solar cells and radial junction solar cells, and on the premise of being fully compatible with existing solar cell preparation processes, proposes an innovative structure and process flow, and provides a graphene Radial heterojunction solar cell and its preparation method, using grazing angle deposition method to grow passivation film, inversion amorphous silicon thin film, graphene and TCO film on single crystal silicon nanocolumn to form p( n)-C-Sia/a-Si passivation film/n(p)-a-Si/graphene/TCO radial structure (as shown in Figure 1), and finally a metal grid line is made on the top of the battery as an electrode. The back field is made at the bottom, and this new structure is expected to improve the conversion efficiency of solar cells and reduce costs.

(2) Technical solution

To achieve the above object, the present invention provides a graphene radial heterojunction solar cell, comprising: a single crystal silicon substrate and a p-type or n-type silicon nanocolumn formed on the single crystal silicon substrate; Single crystal silicon substrate and the passivation film formed sequentially on the p-type or n-type silicon nanocolumn, the amorphous silicon thin film, graphene and TCO film that are inverse to the silicon nanocolumn; the metal gate fabricated on the TCO film electrode; and a back electrode fabricated on the back side of the single crystal silicon substrate.

In the above solution, the single crystal silicon substrate is an n-type single crystal silicon substrate or a p-type single crystal silicon substrate, and its purity is 6N.

In the above solution, the p-type or n-type silicon nanopillars have a diameter of 50nm-4000nm and a height of 10nm-5000nm.

In the above solution, the p-type or n-type silicon nanocolumn and the passivation film formed thereon, the amorphous silicon thin film inverse to the silicon nanocolumn, graphene and TCO film form a radial heterojunction.

In the above solution, the passivation film is a single-layer passivation film or a stacked passivation film. The passivation film is intrinsic amorphous silicon with a thickness of 5 nm.

In the above scheme, when the silicon nanocolumn is a p-type silicon nanocolumn, the amorphous silicon film that is inverse to the silicon nanocolumn is an n-type amorphous silicon film, and when the silicon nanocolumn is an n-type silicon nanocolumn, the The silicon nano-column inverted amorphous silicon thin film is a p-type amorphous silicon thin film.

In the above scheme, the amorphous silicon film that is inverse to the silicon nanocolumn is a doped amorphous silicon film, and for the p-type single crystal silicon substrate, the doped amorphous silicon film is a phosphorus-doped amorphous silicon film, and for n The doped amorphous silicon film is a boron-doped amorphous silicon film for a type single crystal silicon substrate.

In order to achieve the above object, the present invention also provides a method for preparing a graphene radial heterojunction solar cell, comprising: selecting a p-type or n-type single crystal silicon wafer, and preparing a p+p junction or n+n junction on the back side , making silicon nanocolumns on the front surface; forming a passivation film, an amorphous silicon film inverse to the silicon nanocolumns, graphene and a TCO film on the single crystal silicon wafer and the silicon nanocolumns in sequence; on the TCO film making a metal gate electrode; and making a back electrode on the back of the single crystal silicon substrate.

In the above scheme, the sequential formation of a passivation film, an amorphous silicon thin film, graphene and a TCO film on the single crystal silicon wafer and the silicon nanocolumn, including: forming on the single crystal silicon wafer and growing an intrinsic amorphous passivation film on the silicon nanocolumn, the intrinsic amorphous passivation film is a single-layer or stacked passivation film; growing an n-type or p-type heavy duty film on the intrinsic amorphous passivation film Doped amorphous silicon film; transfer and grow graphene layer on the n-type or p-type heavily doped amorphous silicon film; grow TCO film on the graphene layer, the silicon nano-column and the intrinsic amorphous passivation formed sequentially on it Radial heterojunction composed of chemical film, n-type or p-type heavily doped amorphous silicon film, graphene layer and TCO film.

In the above solution, the intrinsic amorphous passivation film, n-type or p-type heavily doped amorphous silicon film, graphene layer or TCO film are all prepared by grazing angle deposition method.

(3) Beneficial effects

As can be seen from the foregoing technical solutions, the present invention has the following beneficial effects:

1. This graphene radial heterojunction solar cell and its preparation method provided by the present invention, intrinsic amorphous passivation film, n-type or p-type heavily doped amorphous silicon film, graphene layer or TCO film all adopt Prepared by the grazing angle deposition method, it can grow a relatively uniform film, avoiding the traditional VLS high-temperature technology, and compatible with the low-temperature process of heterojunction, which is conducive to the improvement of battery efficiency. During the growth of passivation film and inversion amorphous silicon film, the structure and performance of the film are controlled by adjusting the gas flow ratio, deposition temperature and radio frequency power.

2. In the graphene radial heterojunction solar cell and its preparation method provided by the present invention, the absorption of sunlight occurs in the axial direction, which effectively increases the propagation optical path of sunlight in the cell, and the amorphous silicon The absorption coefficient is greater than that of crystalline silicon, which improves the absorption and utilization of light.

3. The graphene radial heterojunction solar cell and its preparation method provided by the present invention will not have the common light-induced degradation effect of amorphous silicon cells by adopting the crystalline silicon/amorphous silicon heterojunction. Adding a passivation layer between the amorphous silicon can reduce the interface state density, reduce the surface recombination, solve the problem of large radial junction surface recombination, and improve the open circuit voltage and fill factor. The bottom requirement is low, and the radial junction has great advantages in carrier transport and collection, which greatly improves the minority carrier lifetime.

4. The graphene radial heterojunction solar cell and its preparation method provided by the present invention combine the newly developed graphene material, make full use of its excellent light transmittance and electrical conductivity, and increase the carrier density. The transmission of light does not increase the absorption of light, which plays a very good role in the collection of carriers.

To sum up, the battery structure of the present invention has many advantages and practical value, has great progress in technology, has good effect, and is suitable for popularization.

Description of drawings

Fig. 1 is a structural representation of a graphene radial heterojunction solar cell according to an embodiment of the present invention; wherein, a single silicon nanocolumn is shown, and its layers are respectively: 1, p-type monocrystalline silicon, 2, Passivation film, 3. N-type heavily doped amorphous silicon film, 4. Graphene thin layer, 5. TCO film, 6. Metal gate, 7. Back field;

2 is a flowchart of a method for preparing a graphene radial heterojunction solar cell according to an embodiment of the present invention;

Fig. 3 is a schematic diagram of the Ag electrode/TCO/graphene/np heterojunction/Al back field structure according to an embodiment of the present invention, and its layers are respectively: 1, p-type single crystal silicon, 2, SiO2 and i-a-Si stacked Layer passivation film, 3. N-type heavily doped amorphous silicon film, 4. Graphene thin layer, 5. TCO film, 6. Ag electrode, 7. Al back field;

Fig. 4 is a schematic diagram of the Ag electrode/TCO/graphene/npp+ junction/graphene/TCO/Ag electrode structure according to an embodiment of the present invention, and its layers are respectively: 1, p-type single crystal silicon, 2, i-a-Si thin film , 3, n-type heavily doped amorphous silicon thin film, 4, p+ amorphous silicon thin film, 5, graphene thin layer, 6, TCO film, 7, Ag electrode.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

As shown in Figure 1, Figure 1 is a schematic structural view of a graphene radial heterojunction solar cell according to an embodiment of the present invention, which solar cell includes: a single crystal silicon substrate and a p p formed on the single crystal silicon substrate type or n-type silicon nanocolumn; passivation film formed sequentially on the single crystal silicon substrate and the p-type or n-type silicon nanocolumn, amorphous silicon thin film, graphene and transparent conductive An oxide (transparent conductive oxide, TCO) film; a metal gate electrode fabricated on the TCO film; and a back electrode fabricated on the back of the single crystal silicon substrate.

Wherein, the single crystal silicon substrate is an n-type single crystal silicon substrate or a p-type single crystal silicon substrate, and its purity is 6N. The p-type or n-type silicon nanocolumn has a diameter of 50nm-4000nm and a height of 10nm-5000nm. The radial heterojunction formed by the p-type or n-type silicon nano-column and the passivation film sequentially formed thereon, the amorphous silicon thin film inverse type to the silicon nano-column, graphene and TCO film. The passivation film is a single-layer passivation film or a laminated passivation film. The passivation film is intrinsic amorphous silicon with a thickness of 5 nm. When the silicon nanocolumn is a p-type silicon nanocolumn, the amorphous silicon thin film that is inverse to the silicon nanocolumn is an n-type amorphous silicon film, and when the silicon nanocolumn is an n-type silicon nanocolumn, the inversion of the silicon nanocolumn is The p-type amorphous silicon film is a p-type amorphous silicon film. The amorphous silicon film that is inverse to the silicon nanocolumn is a doped amorphous silicon film. For a p-type single crystal silicon substrate, the doped amorphous silicon film is a phosphorus-doped amorphous silicon film. For an n-type single crystal silicon The doped amorphous silicon thin film of the substrate is a boron-doped amorphous silicon thin film.

Based on the graphene radial heterojunction solar cell shown in Figure 1, Figure 2 shows the method for preparing this graphene radial heterojunction solar cell, comprising the following steps:

Step 1: Select a p-type or n-type single crystal silicon wafer, prepare a p+p junction or n+n junction on the back surface, and fabricate silicon nanocolumns on the front surface;

Step 2: sequentially forming a passivation film, an amorphous silicon film inverse to the silicon nanocolumn, graphene and a TCO film on the single crystal silicon wafer and the silicon nanocolumn;

Step 3: making a metal gate electrode on the TCO film; and

Step 4: making a back electrode on the back of the single crystal silicon substrate.

In step 2, on the single crystal silicon wafer and the silicon nanocolumn, a passivation film, an amorphous silicon thin film, graphene and a TCO film inverse to the silicon nanocolumn are sequentially formed, including:

growing an intrinsic amorphous passivation film on the single crystal silicon wafer and the silicon nanocolumn, and the intrinsic amorphous passivation film is a single-layer or laminated passivation film;

growing an n-type or p-type heavily doped amorphous silicon film on the intrinsic amorphous passivation film;

Transferring and growing a graphene layer on the n-type or p-type heavily doped amorphous silicon film;

The TCO film is grown on the graphene layer, and the silicon nanocolumn is formed with the intrinsic amorphous passivation film, the n-type or p-type heavily doped amorphous silicon film, the graphene layer and the TCO film in the radial direction. texture.

Wherein, the intrinsic amorphous passivation film, n-type or p-type heavily doped amorphous silicon film, graphene layer or TCO film are all prepared by grazing angle deposition method. Grazing angle deposition technology is to place the substrate at a certain angle on a horizontally rotatable device, and then use electron beam evaporation, magnetron sputtering, chemical deposition and other processes to grow materials on the substrate, which can make the material grow more uniformly. on substrates with complex surface structures.

The present invention is described in further detail below by the operation steps of specific embodiment, but the present invention is not only limited to following embodiment:

Example one

Referring to Figure 1, Figure 1 is a schematic diagram of a single silicon nanocolumn, and its layers are: 1, p-type single crystal silicon, 2, passivation film, 3, n-type heavily doped amorphous silicon film, 4, graphene Thin layer, 5, TCO film, 6, metal gate, 7, back field. The preparation method of the solar cell shown in Figure 1 is as follows:

Step 1: making silicon nanocolumns on p-type single crystal silicon;

Step 2: Cleaning the monocrystalline silicon with the nanopillars by a standard RCA method;

Step 3: hot wire chemical vapor deposition (hot wire chemical vapor deposition, HWCVD) grazing angle deposition SiO ₂ nanometer film, the thickness is about 5-8nm;

Step 4: HWCVD grazing angle deposition of intrinsic amorphous silicon film with a thickness of about 3-10nm;

Step 5: HWCVD grazing angle deposition N-type heavily doped amorphous silicon film, the thickness is about 5-20nm;

Step 6: CVD grazing angle deposition graphene thin layer, the thickness is about 10nm;

Step 7: magnetron sputtering grazing angle deposition TCO film;

Step 8: screen printing low temperature Ag electrodes;

Step 9: Screen Print Al Back Field.

In the above steps, the intrinsic amorphous silicon layer and the SiO ₂ film are used as stacked passivation films to reduce surface recombination.

The specific preparation process in this example is as follows:

①Cleaning process

During the cleaning process, the standard RCA method is used for cleaning, and the silicon wafer after cleaning is blown dry with nitrogen gas, so that there is no water mark or spot.

②HWCVD process

Use multi-chamber HWCVD to deposit SiO ₂ nanometer films, intrinsic amorphous silicon, and n-type amorphous silicon at grazing angles. The substrate is rotated during the deposition process, and the deposition temperature is about 200 ° C to 300 ° C.

③Magnetron sputtering process

Magnetron sputtering is used to deposit TCO at grazing angle, the substrate is rotated during the deposition process, the deposition temperature is 200°C-300°C, and the thickness of the TCO film is about 80nm.

④ Silk screen printing process

Use a screen printing machine to screen-print low-temperature Ag paste and Al paste to form Ag electrodes and Al back fields, avoiding high-temperature sintering steps.

Example two

As shown in Figure 3, Figure 3 is a schematic diagram of the Ag electrode/TCO/graphene/np heterojunction/Al back field structure according to an embodiment of the present invention, and its layers are: 1, p-type single crystal silicon, 2, SiO ₂ and ia-Si laminated passivation film, 3, n-type heavily doped amorphous silicon film, 4, graphene thin layer, 5, TCO film, 6, Ag electrode, 7, Al back field. The preparation method of the solar cell shown in Figure 3 is as follows:

Step 1: making silicon nanocolumns on p-type single crystal silicon;

Step 2: Cleaning the monocrystalline silicon with the nanopillars by a standard RCA method;

Step 3: Use HWCVD to deposit silicon oxide and intrinsic amorphous silicon films on both sides of the monocrystalline silicon wafer at grazing angles, with a thickness of about 3-10nm respectively;

Step 4: Use HWCVD to deposit an n-type heavily doped amorphous silicon film at a grazing angle in the direction of the silicon nanocolumn, with a thickness of about 5-20 nm;

Step 5: Deposit a p+ amorphous silicon film on the back of the silicon wafer by HWCVD, with a thickness of about 5-20nm;

Step 6: Use CVD to deposit a thin layer of graphene on the n-type amorphous silicon with a thickness of about 10nm;

Step 7: Deposit TCO film by double-sided magnetron sputtering at grazing angle;

Step 8: Screen-print low-temperature Ag electrodes on the TCO film;

In the above steps, the p+ amorphous silicon thin film deposited on the back of the silicon wafer and the heterojunction formed by p-type crystalline silicon are used as the back field, and the passivation film is a single-layer intrinsic amorphous silicon thin film.

The specific preparation process in this example is as follows:

①Cleaning process

During the cleaning process, the standard RCA method is used for cleaning, and the silicon wafer after cleaning is blown dry with nitrogen gas, so that there is no water mark or spot.

②HWCVD process

Use multi-chamber HWCVD to deposit intrinsic amorphous silicon, n-type amorphous silicon, and p+ amorphous silicon respectively. The substrate is rotated during the deposition process, and the deposition temperature is about 200°C to 300°C.

③Magnetron sputtering process

Magnetron sputtering is used to deposit TCO at grazing angle, the substrate is rotated during the deposition process, the deposition temperature is 200°C-300°C, and the thickness of the TCO film is about 80nm.

④ Silk screen printing process

Use a screen printing machine to screen-print low-temperature Ag paste to form Ag electrodes, avoiding the high-temperature sintering step.

Example three

As shown in Figure 4, Figure 4 is a schematic diagram of the Ag electrode/TCO/graphene/npp+ junction/graphene/TCO/Ag electrode structure according to an embodiment of the present invention, and its layers are respectively: 1, p-type single crystal silicon, 2. i-a-Si film, 3. n-type heavily doped amorphous silicon film, 4. p+ amorphous silicon film, 5. graphene thin layer, 6. TCO film, 7. Ag electrode. The preparation method of the solar cell shown in Figure 4 is as follows:

Step 1: making silicon nanocolumns on p-type single crystal silicon;

Step 2: Cleaning the monocrystalline silicon with the nanopillars by a standard RCA method;

Step 3: Deposit an intrinsic amorphous silicon film with a thickness of about 3-10nm on both sides of the monocrystalline silicon wafer by HWCVD;

Step 4: Use HWCVD to deposit an n-type heavily doped amorphous silicon film at a grazing angle in the direction of the silicon nanocolumn, with a thickness of about 5-20 nm;

Step 5: Deposit a p+ amorphous silicon film on the back of the silicon wafer by HWCVD, with a thickness of about 5-20nm;

Step 6: Use CVD to deposit a thin layer of graphene on the n-type amorphous silicon with a thickness of about 10nm;

Step 7: Deposit TCO film by double-sided magnetron sputtering at grazing angle;

Step 8: Screen-print low-temperature Ag electrodes on the TCO film;

In the above steps, the p+ amorphous silicon thin film deposited on the back of the silicon wafer and the heterojunction formed by p-type crystalline silicon are used as the back field, and the passivation film is a single-layer intrinsic amorphous silicon thin film.

The specific preparation process in this example is as follows:

①Cleaning process

During the cleaning process, the standard RCA method is used for cleaning, and the silicon wafer after cleaning is blown dry with nitrogen gas, so that there is no water mark or spot.

②HWCVD process

Use multi-chamber HWCVD to deposit intrinsic amorphous silicon, n-type amorphous silicon, and p+ amorphous silicon respectively. The substrate is rotated during the deposition process, and the deposition temperature is about 200°C to 300°C.

③Magnetron sputtering process

Magnetron sputtering is used to deposit TCO at grazing angle, the substrate is rotated during the deposition process, the deposition temperature is 200°C-300°C, and the thickness of the TCO film is about 80nm.

④ Silk screen printing process

Use a screen printing machine to screen-print low-temperature Ag paste to form Ag electrodes, avoiding the high-temperature sintering step.

It can be seen from the above embodiments that the present invention relates to a graphene radial heterojunction solar cell and its preparation method. The preparation process of the present invention combines the production process of radial junction solar cells and the production process of heterojunction solar cells. The cells of this structure include p or n type single crystal silicon nanocolumns, passivation film, n type or p Type heavily doped amorphous silicon film, graphene thin layer, TCO film, the metal grid on the top of the battery as the electrode and the back field, the battery prepared by this method can combine the advantages of radial junction battery and heterojunction battery, using The high-efficiency and low-temperature process of heterojunction cells can indirectly reduce production costs. At the same time, radial junctions can effectively improve the absorption and utilization of light and improve the collection efficiency of photogenerated carriers, thereby effectively improving the efficiency of cells, and using graphene The conductivity of the electrode improves the collection effect of the electrode on the current, and the short-circuit current is increased. At the same time, the low-temperature process of the heterojunction is used, the preparation process is simple, and the temperature stability is good, which is suitable for large-scale popularization and application.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (11)

1. Graphene heterojunction solar battery radially is characterized in that, comprising:

Monocrystalline substrate and be formed at p type or n type silicon nano-pillar on this monocrystalline substrate;

The passivating film that on this monocrystalline substrate and this p type or n type silicon nano-pillar, forms successively, with amorphous silicon membrane, Graphene and the TCO film of silicon nano-pillar transoid;

The metal gate electrode of on this TCO film, making; And

The back electrode of making at this monocrystalline substrate back side.

2. Graphene according to claim 1 is heterojunction solar battery radially, it is characterized in that, described monocrystalline substrate is n type monocrystalline substrate or p type monocrystalline substrate, and its purity is 6N.

3. Graphene according to claim 1 is heterojunction solar battery radially, it is characterized in that, described p type or n type silicon nano-pillar, and its diameter is 50nm-4000nm, highly is 10nm-5000nm.

4. Graphene according to claim 1 is heterojunction solar battery radially, it is characterized in that the radially heterojunction that this p type or n type silicon nano-pillar and the passivating film that forms successively on it, the amorphous silicon membrane with silicon nano-pillar transoid, Graphene and TCO film constitute.

5. according to claim 1 or 4 described Graphenes heterojunction solar battery radially, it is characterized in that described passivating film is individual layer passivation film or lamination passivation film.

6. Graphene according to claim 5 is heterojunction solar battery radially, it is characterized in that, described passivating film is an intrinsic amorphous silicon, and thickness is 5nm.

7. Graphene according to claim 1 is heterojunction solar battery radially, it is characterized in that, described and amorphous silicon membrane silicon nano-pillar transoid are n type amorphous silicon membrane when the silicon nano-pillar is p type silicon nano-pillar, and described and amorphous silicon membrane silicon nano-pillar transoid are p type amorphous silicon membrane when the silicon nano-pillar is n type silicon nano-pillar.

8. Graphene according to claim 1 is heterojunction solar battery radially, it is characterized in that, described and amorphous silicon membrane silicon nano-pillar transoid is a doped amorphous silicon film, for this doped amorphous silicon film of p type monocrystalline substrate is phosphorus-doped amorphous silicon thin film, is the boron mixing non-crystal silicon thin film for this doped amorphous silicon film of n type monocrystalline substrate.

9. one kind prepares in the claim 1 to 8 the radially method of heterojunction solar battery of each described Graphene, it is characterized in that, comprising:

Select p type or n type monocrystalline silicon piece for use, prepare p+p knot or n+n knot overleaf, make the silicon nano-pillar at front surface;

On this monocrystalline silicon piece and this silicon nano-pillar, form successively passivating film, with amorphous silicon membrane, Graphene and the TCO film of silicon nano-pillar transoid;

On this TCO film, make metal gate electrode; And

Make back electrode at this monocrystalline substrate back side.

10. the radially method of heterojunction solar battery of Graphene for preparing according to claim 9, it is characterized in that, described on this monocrystalline silicon piece and this silicon nano-pillar, form successively passivating film, with amorphous silicon membrane, Graphene and the TCO film of silicon nano-pillar transoid, comprising:

Growth intrinsic amorphous passivating film on this monocrystalline silicon piece and this silicon nano-pillar, this intrinsic amorphous passivating film is individual layer or lamination passivating film;

Growing n-type or the heavily doped amorphous silicon film of p type on this intrinsic amorphous passivating film;

Transforming growth graphene layer on this n type or the heavily doped amorphous silicon film of p type;

Growth TCO film on this graphene layer, the radially heterojunction that this silicon nano-pillar and the intrinsic amorphous passivating film, n type or the heavily doped amorphous silicon film of p type that form successively on it, graphene layer and TCO film constitute.

11. the radially method of heterojunction solar battery of Graphene for preparing according to claim 10 is characterized in that, described intrinsic amorphous passivating film, n type or the heavily doped amorphous silicon film of p type, graphene layer or TCO film all adopt plunders angle sedimentation preparation.

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