130 results about "Phosphorus diffusion" patented technology

The present disclosure belongs to the technical field of the preparation of hybrid passivated back-contact cells, and specifically relates to a short-process preparation method for a hybrid passivated back-contact cell and the use thereof. The short-process preparation method comprises: S1, texturing both surfaces of a silicon wafer; S2, subjecting the front surface of the silicon wafer to phosphorus diffusion, so as to form a third semiconductor diffusion region, wherein the process of phosphorus diffusion comprises the steps of first performing low-temperature diffusion and then performing cooling and discharging, and during the period, heating is not performed to promote diffusion; S3, removing a diffusion layer that detours to and coats the back surface and a phosphorosilicate glass layer on the front surface, which are both obtained in S2; S4, sequentially depositing a first semiconductor layer and a mask layer on the back surface obtained in S3, and subjecting same to high-temperature annealing crystallization at the same time; S5, forming a second semiconductor opening region; and S6, forming an anti-reflection layer on the front surface of the silicon wafer. In the present disclosure, a passivation effect is good, and the film density is better; moreover, defects such as film holes are effectively ameliorated, the cell conversion efficiency and the cell yield are substantially improved, and the technological process is greatly simplified, thereby greatly reducing the equipment investment cost.

The invention discloses a preparation method of a solar cell, which belongs to the technical field of solar cells and comprises the following steps of: selecting an N-type silicon substrate and performing double-sided texturing; performing boron diffusion doping on the front surface of the silicon substrate to form a P + doping layer and a borosilicate glass layer on the front surface, and forming a borosilicate glass layer on the back surface; removing the borosilicate glass layer on the back surface of the N-type silicon substrate, and carrying out alkali washing and polishing on the back surface of the N-type silicon substrate; forming a polycrystalline silicon layer and a polycrystalline silicon layer on the back and the front of the substrate; performing phosphorus diffusion on the polycrystalline silicon layer on the substrate; removing the phosphorosilicate glass layer on the front side, the borosilicate glass layer, the N + polycrystalline silicon layer and the borosilicate glass layer and the phosphorosilicate glass layer on the back side; depositing a front passivation layer and a front antireflection layer on the P + doping layer on the front of the substrate; electrode printing sintering is carried out on the front and back of the substrate; the reverse bias voltage applied by the first LECO process is 3-10V, and the reverse bias voltage applied by the second LECO process is 11-20V. And the black edge problem caused by overburning is reduced by increasing the LECO for the second time.

The invention discloses a TBC solar cell and a preparation method thereof. The preparation method of the TBC solar cell comprises the following steps: cleaning and polishing an N-type silicon substrate; depositing a first tunneling oxide layer and a first intrinsic polycrystalline silicon layer on the back surface; boron diffusion; performing laser grooving, etching and cleaning; depositing a second tunneling layer and a second intrinsic polycrystalline silicon layer on the back surface; phosphorus diffusion; performing laser grooving, etching and cleaning; depositing an aluminum oxide film and an anti-reflection film on two sides; and preparing a metal electrode. According to the invention, the phosphorus-doped polycrystalline silicon layer is added on the boron-doped polycrystalline silicon layer, the second tunneling layer of the interlayer can form a secondary gettering effect, and the passivation level of the boron-doped polycrystalline silicon layer is improved. A built-in electric field formed by the two PN junctions generates more carriers, more holes are forced to be gathered and transversely transmitted at the boron-doped polycrystalline silicon layer and more easily collected by a metal electrode, and a back suede structure and a carrier collection optimization structure are added on the basis of not increasing the process flow.

The invention discloses a preparation method of a solar cell and the solar cell, and the preparation method comprises the steps: firstly providing an N-type silicon substrate, carrying out boron diffusion doping processing on one side of a first surface of the N-type silicon substrate, and carrying out phosphorus diffusion doping processing on one side of a second surface of the N-type silicon substrate; wherein the first surface and the second surface are two surfaces, deviating from each other, of the N-type silicon substrate, the first surface is a suede surface, the second surface is a polished surface, then a first passive film layer is formed on the first surface, a second passive film layer is formed on the second surface, and finally a main-grid-free process is adopted. And carrying out silk-screen printing and sintering treatment on one side of the first passive film layer and / or one side of the second passive film layer to form a plurality of fine grids, and preparing the solar cell. By means of the method, the effective utilization area of the surface of the solar cell is increased, excessive occupation of the surface area of the solar cell due to arrangement of the main grid is reduced, and the effect that the whole solar cell is high in photoelectric conversion efficiency is achieved.

The invention discloses a passivation method of a boron and phosphorus doped Poly layer, a passivation contact structure of the boron and phosphorus doped Poly layer and a battery. The passivation method comprises the following steps: firstly, growing a tunneling oxide layer with two thin and compact sides and a thick and loose middle on the surface of a silicon wafer by adopting a mode of combining low-temperature low-pressure oxidation, high-temperature normal-pressure oxidation and low-temperature normal-pressure oxidation, and then carrying out deposition and oxidation propulsion of boron atoms and / or phosphorus atoms by adopting a high-temperature diffusion tube, so that boron and phosphorus with a certain concentration are doped in a Poly silicon layer. According to the invention, through superposition of the oxide layers with different compactness, the overall thickness of the tunneling oxide layer is improved, so that the structure of the tunneling oxide layer is not obviously damaged in the subsequent boron and phosphorus diffusion process, and the passivation effect of the boron and phosphorus doped Poly layer is obviously improved. According to the passivation method disclosed by the invention, Poly silicon layers and doped polycrystalline silicon layers with different thicknesses can be obtained, and the passivation method can be applied to all batteries needing to use boron Poly and phosphorus Poly.

The invention discloses a preparation method of a TBC battery electrode grid line, the electrode grid line and a TBC battery, and belongs to the technical field of solar cells, and the preparation method comprises the following steps: carrying out double-sided polishing on a silicon wafer; sequentially depositing a tunneling oxide layer and an intrinsic polycrystalline silicon layer on the back surface of the silicon wafer, and performing boron diffusion; digging an N region and a PN connection partition region on the back surface of the silicon wafer; sequentially depositing a tunneling oxide layer and an intrinsic polycrystalline silicon layer on the back surface of the silicon wafer, and performing phosphorus diffusion on the basis of the tunneling oxide layer and the intrinsic polycrystalline silicon layer; digging a P region and a GAP region on the back surface of the silicon wafer, and digging a hole channel by using a second laser; removing the borosilicate glass layer and the phosphorosilicate glass layer in the pore channel area; sequentially depositing an aluminum oxide layer and a silicon nitride layer on the surface of the silicon wafer; printing non-burn-through slurry in the main grid areas of the P area and the N area through the silk screen printing plate; and carrying out laser-assisted sintering on the auxiliary grid line pore channel region. The completeness of a passivation film layer structure on the back surface of the battery piece is ensured, meanwhile, the contact area of a metal electrode and a silicon substrate is reduced, and metal contact recombination is effectively reduced.

The invention relates to a preparation process of a TBC battery. The TBC battery comprises a substrate; the substrate is polished and cleaned; the doping treatment process comprises a first doping process and a second doping process, the first doping process is used for carrying out boron diffusion, and the second doping process is used for carrying out phosphorus diffusion; performing a high-temperature annealing process of high-temperature junction pushing on the substrate treated by the doping treatment process; carrying out PSG removal and front surface and side surface alkali polishing processes on the substrate treated by the high-temperature annealing process; and depositing an aluminum oxide layer, a silicon nitride layer and an electrode on the substrate. Boron expansion and phosphorus expansion are respectively carried out on the substrate, and junction pushing is not carried out; boron diffusion and phosphorus diffusion knot pushing processes are carried out in the same high-temperature environment, so that the thermal history is shortened, the energy consumption is reduced, the process flow is simplified, the production cost is reduced, and the production efficiency is improved.

The invention provides a TBC battery, a preparation method thereof and a photovoltaic module, and relates to the technical field of solar cells, and the front surface structure of the TBC battery comprises an N + front surface field layer, a front phosphorosilicate glass layer, a passive film layer and an antireflection film layer which are sequentially stacked on the front surface of a silicon substrate; wherein the N + front surface field layer is a high-concentration N-type region formed by doping phosphorus atoms on the front surface through phosphorus diffusion. An N + front surface field (FSF) is added on the front surface of the cell, phosphorus atoms are doped on the front surface through phosphorus diffusion to form an N + region, an N-N + high-low junction is formed with an N-type silicon substrate, minority carriers are repelled, and the field passivation effect is improved.

The invention relates to the technical field of solar cells, and discloses a TBC cell and a preparation method thereof.The preparation method comprises the steps that a tunneling layer and an intrinsic amorphous silicon layer are prepared on the back face of a silicon wafer; a first barrier layer is locally prepared on the back surface of the intrinsic amorphous silicon layer; boron diffusion enables the intrinsic amorphous silicon layer in a non-first barrier layer region to be converted into a boron-doped polycrystalline silicon layer; removing the local first barrier layer through laser patterning to expose the intrinsic amorphous silicon layer in a laser area; performing wet etching to form a Gap region, and exposing the boron-doped polycrystalline silicon layer and the intrinsic amorphous silicon layer in a non-laser region; locally preparing a second barrier layer on the back surfaces of the Gap region silicon wafer and the boron-doped polycrystalline silicon layer; phosphorus diffusion enables the exposed intrinsic amorphous silicon layer to be converted into a phosphorus-doped polycrystalline silicon layer; removing the second barrier layer and performing texturing; according to the method, the Gap region can be easily formed, the boron-doped polycrystalline silicon layer and the phosphorus-doped polycrystalline silicon layer have no height difference, the working procedures are few, the damage is little, the cost is low, and the battery efficiency can be improved.

The invention relates to a solar cell, a preparation method thereof and a photovoltaic module, a substrate is provided, a tunneling layer, a polycrystalline silicon layer, a borosilicate glass layer and a phosphorosilicate glass layer which are laminated are formed on the back surface of the substrate along a direction far away from the substrate, and the polycrystalline silicon layer comprises first areas and second areas which are alternated; laser acts on the borosilicate glass layer and the part, located in the first area, of the phosphorosilicate glass layer, so that boron in the borosilicate glass layer is diffused into the polycrystalline silicon layer, and a first polarity area is formed in the first area; the preset temperature acts on the borosilicate glass layer and the part, located in the second area, of the phosphorosilicate glass layer, so that phosphorus in the phosphorosilicate glass layer is diffused into the polycrystalline silicon layer, and a second polarity area is formed in the second area; removing the residual borosilicate glass layer and phosphorosilicate glass layer on the polycrystalline silicon layer; a first electrode is formed in the first polar region, and a second electrode is formed in the second polar region. According to the preparation method, the high-temperature step can be reduced, the cost can be reduced, the process time can be shortened, and the productivity can be improved.

The invention relates to the photovoltaic field, and discloses a hot spot prevention structure of a back contact battery and a preparation method of the hot spot prevention structure. According to the hot spot prevention structure of the back contact battery, the boron-doped layer and the extended phosphorus-doped layer are disconnected through the gap; wherein the boron diffusion layer and the phosphorus diffusion layer can form a conductive channel, the conductive channel is located in the semi-silicon substrate and is formed by diffusing boron / phosphorus atoms into the silicon substrate and diffusing the boron / phosphorus atoms to the periphery, and the design can avoid generation of larger conduction electric leakage. According to the hot spot prevention structure of the back contact battery, the electric leakage loss can be effectively reduced on the basis of reducing the risk of generating a hot spot effect at the assembly end.

The method for passivating the side face of the battery piece comprises the following steps that S1, texturing treatment is carried out; s2, boron diffusion; s3, removing the edge of the back surface and the borosilicate glass at the edge; s4, performing alkali polishing on the back surface, removing the phosphorus-doped polycrystalline silicon layer wound and expanded on the edge and the back surface, and reserving the phosphorus-doped polycrystalline silicon layer and the borosilicate glass layer on the front surface; s5, depositing on the back surface of the polished silicon wafer to form a tunneling oxide layer; s6, phosphorus diffusion; s7, removing phosphorosilicate glass layers on the front surface and the edge by using HF; s8, RCA cleaning is carried out; s9, using laser slicing to divide the battery piece into two parts; s10, passivating the boron diffusion surface and the front surface to form an aluminum oxide layer; s11, film coating is carried out; according to the invention, the power output is increased, the power of the module can be improved by 6-8 W by combining the N-type TOPCon technology, and the efficiency is improved by more than 0.2%.

The invention discloses a passivation contact cell with a selective Poly structure, a preparation method of the passivation contact cell and a photovoltaic module. The passivation contact cell comprises an N-type silicon wafer substrate, a metal contact area and a non-metal contact area, wherein the metal contact area is sequentially provided with a phosphorus diffusion layer, a tunneling oxide layer, a phosphorus-doped polycrystalline silicon layer and a back surface passivation anti-reflection film from inside to outside; the non-metal contact region comprises a third region with phosphorus diffusion and a fourth region with a recess on the silicon substrate, the third region is sequentially provided with a phosphorus diffusion layer and a back surface passivation anti-reflection film from inside to outside, and the fourth region is provided with a back surface passivation anti-reflection film on the surface of the recess structure. According to the passivation contact battery, the transverse transmission of back current can be improved, the filling factor of the battery is improved, and the Voc of the battery can be prevented from being greatly reduced. And the optical performance of the cell can be remarkably improved, and the long-wave quantum efficiency is improved, so that the current and double-sided rate of the cell are improved.

The invention relates to the technical field of solar cells, in particular to a TOPCon solar cell and a preparation method thereof. The preparation method comprises the steps of front surface texturing, boron diffusion, removal of BSG + alkali polishing, deposition of a back surface insulating layer, local grooving on the insulating layer, deposition of a tunneling oxide layer and a polycrystalline silicon layer in sequence in a local grooving area, phosphorus diffusion, removal of PSG + RCA, deposition of a passivation layer and an anti-reflection film layer, and silk-screen printing. According to the method, the insulating layer is deposited on the back surface of the silicon wafer, local grooving is carried out, the oxide layer / polycrystalline silicon layer and the printing electrode are tunneled in the grooving area, non-contact passivation is reserved, meanwhile, the carrier transmission path is optimized, the recombination loss is reduced, the passivation performance of the battery prepared through the method can be further optimized, and the service life of the battery is prolonged. The conversion efficiency of the battery is improved.

To restrain failure of a device by reducing phosphorus diffusion to an epitaxial layer from a substrate side at the time of heat treatment of a device manufacturing step, while restraining stacking fault of epitaxial layers.SOLUTION: A silicon substrate manufacturing method includes: a step of adding phosphorus as a dopant, and growing a silicon single crystal with electric resistivity of 0.9 mΩ cm or less; and a step of cutting a silicon semiconductor substrate from the silicon single crystal. A transit time Y(min) between 700°C or less and 600°C or more in an area of the silicon single crystal, in which the silicon substrate with electric resistivity R is positioned, is controlled to satisfy formulae (1) and (2).SELECTED DRAWING: Figure 1

The invention discloses a phosphorus diffusion method for improving photoelectric conversion efficiency of a BC type battery, which realizes high sheet resistance (20-150 omega) with excellent uniformity while obtaining high impurity concentration PSG by improving a phosphorus diffusion process after an N-type BC type battery LP route N-poly, thereby improving FF of the BC type battery, reducing contact resistance Rs and finally improving the photoelectric conversion efficiency of the battery to a greater extent. And secondly, a multi-step source-passing method is adopted, the source-passing time is shortened, the source-passing flow is increased, rapid temperature rise propulsion and the like are adopted, a conventional phosphorus diffusion method is changed, high sheet resistance with excellent uniformity is realized while high-impurity-concentration PSG is obtained, reduction of N-region carrier recombination is ensured, FF and Uoc are improved, and finally the conversion efficiency of the battery is improved to the maximum extent.

The invention provides a TBC battery and a preparation method thereof. The current density is remarkably improved by adjusting printing and laser patterns, reducing the area of a P region or / and an N region, increasing the area of a gap region, reducing the metal shielding area and improving the photon utilization rate; and compounding of a metal region is reduced, and Voc and passivation performance of the battery piece are improved. By polishing the gap region with the pyramid suede, the reflection of incident light in the silicon substrate can be increased, so that the Isc of the cell is improved, and meanwhile, as the initial gap region is protected by the mask layer and is not damaged by wet corrosion subsequently, the height difference between the gap region and the boron / phosphorus diffusion layer can be reduced, the transverse transmission of carriers in the silicon substrate is facilitated, and the FF is improved. According to the TBC battery prepared by the method, under the condition that the number of partitions on the back surface of the battery is not changed, the areas of the P region and the N region are reduced, so that the area of the gap region is increased, the metal shielding area is reduced, the photon utilization rate is improved, and the current density is obviously improved; and compounding of a metal region is reduced, and Voc and passivation performance of the battery piece are improved.

The present invention relates to the field of solar cells, and discloses a method for preparing a TBC solar cell with a convex isolation region structure. Firstly, the present invention can prepare a TBC solar cell with a convex isolation region structure through an ingenious preparation method, which can not only reduce the probability of short circuit between the p region (boron diffusion region) and the n region (phosphorus diffusion region), but also reduce the thickness of part of the boron diffusion layer or the phosphorus diffusion layer to reduce the influence of parasitic absorption; secondly, the present invention optimizes the process steps to achieve a TBC solar cell by depositing an intrinsic polysilicon layer once, which can effectively improve the performance and yield of the product, and at the same time significantly reduce the production cost.

The invention relates to a solar cell and a preparation method thereof, and a photovoltaic module. The preparation method comprises the following steps: providing a substrate, and forming a tunneling layer and a polycrystalline silicon layer on the back surface of the substrate; a borosilicate glass layer is formed on the polycrystalline silicon layer, and laser acts on the part, located in the first region of the polycrystalline silicon layer, of the borosilicate glass layer, so that boron in the borosilicate glass layer is diffused to the first region of the polycrystalline silicon layer to form a first polarity region; a phosphorosilicate glass layer is formed on the polycrystalline silicon layer, and laser acts on the part, located in the second area of the polycrystalline silicon layer, of the phosphorosilicate glass layer, so that phosphorus in the phosphorosilicate glass layer is diffused to the second area of the polycrystalline silicon layer to form a second polarity area; respectively removing the residual borosilicate glass layer and phosphorosilicate glass layer on the polycrystalline silicon layer; a first electrode is formed in the first polar region, and a second electrode is formed in the second polar region. Compared with the related technology, the preparation process has the advantages that the high-temperature step can be reduced, the cost can be reduced, the process time can be shortened, and the productivity of solar cells and photovoltaic modules can be improved.

The present invention relates to the field of solar cells. Disclosed are a lateral-vertical composite multi-junction TBC solar cell and a manufacturing method therefor. The TBC solar cell comprises an N-type silicon wafer. The front surface of the N-type silicon wafer is sequentially provided with a pyramid textured surface and a passivation layer; the back surface of the N-type silicon wafer is provided with a deposition region A and a deposition region B distributed in an interdigitated manner; a gap between the deposition region A and the deposition region B serves as an isolation region, and the surface of the isolation region is sequentially provided with the pyramid textured surface and the passivation layer; the surface of the deposition region A is sequentially provided with a boron diffusion layer A, a phosphorus diffusion layer A, a tunneling oxide layer A, a phosphorus diffusion layer B, the passivation layer and an electrode layer; the surface layer of the N-type silicon wafer located at the bottom of the deposition region B is a boron diffusion layer B, and the surface of the deposition region B is sequentially provided with a tunneling oxide layer B, a boron diffusion layer C, the passivation layer and the electrode layer. The TBC solar cell of the present invention has a lateral-vertical composite multi-junction structure, which is beneficial to further improving the cell conversion efficiency of the cell and also reducing the manufacturing cost and technical difficulty of the cell.

The invention discloses a phosphorus diffusion process in a downstream wafer insertion mode, which comprises the following steps of: vertically inserting a silicon wafer into a quartz boat, loading the quartz boat into a furnace tube of a diffusion furnace, enabling the silicon wafer to be vertical to the radial direction of the furnace tube, oxidizing at 730-760 DEG C, cooling to 700-720 DEG C, feeding air in sections, depositing the silicon wafer, heating to 830-890 DEG C, propelling, cooling, and returning pressure, and finishing the treatment. According to the phosphorus diffusion process, the number of inserted wafers can be increased to 2880 wafers per boat, the productivity can be increased by 70% or above, the heating power can be controlled and output at a constant speed and slowly by adopting a mode of'heating oxidation + cooling diffusion + heating propulsion ', the difference between the edge temperature and the center temperature of the silicon wafer can be reduced, and the yield of the silicon wafer can be improved. Therefore, the diffusion uniformity can be improved under the condition of lower energy consumption, and the method has the advantages of high productivity, good diffusion uniformity and the like, can be widely used for preparing high-rate solar cells, and is high in use value and good in application prospect.

The application discloses a TBC solar cell and a preparation method thereof. The preparation method comprises two boron diffusion steps and two phosphorus diffusion steps, and a first dense tunneling oxide layer, a first non-dense tunneling oxide layer, a second dense tunneling oxide layer and a second non-dense tunneling oxide layer are deposited. While ensuring that the first and second polycrystalline silicon layers have high doping concentrations, the first and second dense tunneling oxide layers effectively prevent the diffusion depth of doping ions in the silicon substrate, thereby improving the collection efficiency of carriers and maintaining good passivation effects. In addition, the first electrode grid is embedded in the first non-dense tunneling oxide layer, and the second electrode grid is embedded in the second non-dense tunneling oxide layer, so that the contact effect is good, the absorption efficiency of the first and second electrode grids for the carriers transported in the transverse direction is enhanced, and compared with the prior art, the process difficulty is low and the error rate is low.

The application relates to the field of solar cell manufacturing, and particularly discloses a TOPCon cell and a preparation method thereof. A front surface oxidation layer is obtained by front surface oxidation of a silicon substrate; a back surface oxidation layer and a polysilicon layer are sequentially arranged on the back surface of the silicon substrate; a SE area of the front surface oxidation layer is laser grooved to obtain a diffusion precursor, grooves on the front surface of the diffusion precursor penetrate the front surface oxidation layer; boron diffusion is performed on the front surface of the diffusion precursor to obtain a cell precursor; after back surface phosphorus diffusion, surface passivation and electrode arrangement are performed on the cell precursor, the TOPCon cell is obtained. The TOPCon cell is produced by only one diffusion, so that the process flow is simplified, the service life of a reaction furnace is greatly prolonged, the demand for boron diffusion reagents in the production process is reduced, and the production cost is greatly reduced.

The invention discloses a photovoltaic silicon wafer back diffusion process and a TOPCon battery. The photovoltaic silicon wafer back diffusion process provided by the invention comprises the following steps: carrying out phosphorus diffusion treatment on the back of a silicon wafer after alkali polishing, and oxidizing a dead layer on the back to form a phosphorosilicate glass layer; carrying out annealing treatment on the silicon wafer with the phosphorosilicate glass layer so as to promote the diffusion of phosphorus elements on the back surface of the silicon wafer; and removing the residual phosphorosilicate glass layer on the back surface of the silicon wafer by adopting etching treatment. By adopting the method, the contact resistivity of the silicon wafer can be reduced, the filling factor FF can be improved, and the efficiency of a TOPCon battery manufactured by adopting the silicon wafer can be further improved.

The application discloses a Topcon battery and a preparation method thereof, a solar module and a solar system, and relates to the technical field of solar cells. The preparation method of the Topcon battery comprises the following steps: step 1, providing a substrate, and performing a texturing treatment on the surface of the substrate; step 2, obtaining a P+ layer through boron doping and BSG removal; step 3, obtaining a tunneling oxide layer and a doped polysilicon layer by adopting LPCVD and high-temperature phosphorus diffusion; step 4, obtaining an aluminum oxide layer on the front surface of the substrate by adopting ALD; step 5, obtaining a front surface silicon nitride layer on the front surface of the substrate by adopting PECVD; step 6, obtaining a back surface silicon nitride layer on the back surface of the substrate by adopting PECVD, and modifying the doped polysilicon layer, so that a polysilicon layer doped with carbon elements is formed on the surface of the doped polysilicon layer. The application does not need to increase additional equipment, is compatible with the existing LPCVD equipment for preparing the Topcon battery containing the polysilicon layer doped with carbon elements, is simple to operate, low in cost and suitable for large-scale popularization.

Provided are N-type monocrystalline silicon double-sided solar cell and preparation method thereof. Preparation method includes following steps: S1: performing double-sided texturing to obtain N-type monocrystalline silicon with front surface and back surface having first textured structures respectively; S2: performing back-surface phosphorus diffusion doping to form back surface field; S3: removing winding plating and PSG on front surface and back surface, forming mask for protecting first textured structure of back surface on surface of back surface field, and manufacturing second textured structure on front surface of N-type monocrystalline silicon; S4: performing front-surface boron diffusion doping to form front-surface doped emitter junction layer; S5: after removal of mask, winding plating and BSG on front surface and back surface, depositing passivation antireflection layer on surface of front-surface doped emitter junction layer, and depositing passivation layer on surface of back surface field; and S6: preparing front surface electrode and back surface electrode.

The invention discloses a preparation method of a BC solar cell, and relates to the technical field of BC cell preparation, and the method specifically comprises the steps: selecting an N-type silicon wafer, and carrying out the alkali polishing treatment; depositing a tunneling oxide layer and a first intrinsic silicon layer on a single side; performing phosphorus expansion treatment to form N-type polycrystalline silicon; depositing a silicon nitride passivation layer on the back surface; a pyramid structure is formed on the front side through alkali texturing; sequentially depositing aluminum oxide and a silicon nitride passivation layer on the front surface; carrying out annealing treatment; performing laser grooving to remove the silicon nitride, the polycrystalline silicon and the tunneling layer; depositing second intrinsic silicon and P-type silicon on the back surface; performing secondary laser grooving to form a PN junction; depositing a TCO thin film on the back surface; printing an electrode to obtain a finished battery. The silicon nitride is used as the passivation layer and the laser mask, traditional photoresist is replaced, the process is simplified, the cost is reduced, the passivation effect and open-circuit voltage are improved through aluminum oxide and silicon nitride laminated passivation, the current transmission efficiency is improved through the TCO thin film, the efficiency of the cell prepared through the method is higher than that of a traditional cell, and the method has good application prospects.

The invention discloses a TOPCon battery capable of improving minority carrier lifetime and a preparation method thereof, and belongs to the field of TOPCon batteries, and the preparation method comprises the following steps: sequentially carrying out pre-cleaning, two times of phosphorus diffusion, surface PSG removal, texturing treatment, boron diffusion and other post-treatments on a silicon wafer to prepare the TOPCon battery. The method has the beneficial effects that deposition gettering is carried out on the silicon wafer through two times of phosphorus diffusion and gradient temperature rise propulsion, and the method has a better gettering effect for the silicon wafer with seriously low minority carrier lifetime. In addition, the concentration of chemicals in the texturing cleaning and rough polishing tank is reduced, the silicon wafer can be prevented from being seriously thinned due to secondary rough polishing, the concentration of the chemical liquid in the texturing tank is adjusted, the concentration of the additive is increased, the texturing rate is controlled, and the damage to the silicon wafer is reduced to the minimum.

The application discloses a preparation method of a TBC solar cell, which comprises the following steps: dipping a substrate into a specified solution at a predetermined temperature to perform texturing, and controlling the texturing time within a predetermined time; sequentially depositing a tunneling oxide layer and an intrinsic polysilicon layer on the back of the substrate; depositing a mask layer on the side of the intrinsic polysilicon layer away from the tunneling oxide layer; forming a first opening area on the mask layer, and performing boron diffusion on the first opening area to form a boron-doped polysilicon layer; forming a second opening area on the mask layer, and performing phosphorus diffusion on the second opening area to form a phosphorus-doped polysilicon layer; the mask layer remains between the first opening area and the second opening area; and depositing an anti-reflection layer on the back of the substrate. The application can shorten the production process and reduce the risk of laser damage to the cell.

A process for manufacturing a bifacial photovoltaic cell, comprising the steps: coating a substrate with a boron containing layer; forming a cap layer over the boron containing layer which is on the second surface of the substrate; removing the boron containing layer from the surfaces of the substrate which are not covered with a cap layer; effecting the deposition of a phosphorous containing layer on the surfaces of the substrate which are not covered by the cap layer, and effecting diffusion of the phosphorous and the boron into the substrate; removing the phosphorous containing layer; texturing the substrate where there is no cap layer; effecting the deposition of a phosphorous containing layer on the first surface of the substrate and effecting diffusion of phosphorous into the substrate to form a second n-doped layer; and forming a passivating and / or antireflective coating layer covering the n-doped layer on the substrate's first surface.