JP6411604B2 - Solar cell - Google Patents

Description

  Embodiments of the subject matter described herein generally relate to solar cell manufacturing. More particularly, the subject embodiments relate to thin silicon solar cells and techniques for manufacturing.

  A solar cell is a well-known device that converts solar radiation into electrical energy. Solar cells may be manufactured on a semiconductor wafer using semiconductor process technology. The solar cell includes P-type and N-type diffusion regions. When solar cells are exposed to sunlight, electrons and holes are generated, and these electrons and holes move to the diffusion region, thereby generating a voltage difference between the diffusion regions. In back contact solar cells, the diffusion regions and metal contact fingers bonded to these diffusion regions are both on the back surface of the solar cell. This contact finger allows an external electrical circuit to be coupled to the solar cell and to receive power from the solar cell.

  Efficiency is an important characteristic of solar cells because it is directly related to the ability of the solar cell to generate power. Therefore, techniques that improve the manufacturing process, reduce manufacturing costs, and increase the efficiency of solar cells are generally desirable. Such techniques include forming polysilicon and heterojunction layers on a silicon substrate by a thermal process. With this thermal process, the present invention enables solar cell efficiency. These or other similar embodiments form the background of the present invention.

  A more complete understanding of the present subject matter can be derived by considering and referring to the following detailed description and claims in conjunction with the following drawings. Like reference numbers refer to like elements throughout the drawings.

It is sectional drawing of the solar cell manufactured according to embodiment of this invention. It is sectional drawing of the solar cell manufactured according to embodiment of this invention. It is sectional drawing of the solar cell manufactured according to embodiment of this invention. It is sectional drawing of the solar cell manufactured according to embodiment of this invention. It is sectional drawing of the solar cell manufactured according to embodiment of this invention. It is sectional drawing of the solar cell manufactured according to embodiment of this invention. It is sectional drawing of the solar cell manufactured according to embodiment of this invention. It is sectional drawing of the solar cell manufactured according to embodiment of this invention. It is sectional drawing of the solar cell manufactured according to embodiment of this invention. It is sectional drawing of the solar cell manufactured according to embodiment of this invention. It is sectional drawing of the solar cell manufactured according to embodiment of this invention. It is sectional drawing of the solar cell manufactured according to embodiment of this invention.

FIG. 6 is a cross-sectional view of a solar cell being manufactured according to another embodiment of the present invention. FIG. 6 is a cross-sectional view of a solar cell being manufactured according to another embodiment of the present invention. FIG. 6 is a cross-sectional view of a solar cell being manufactured according to another embodiment of the invention. FIG. 6 is a cross-sectional view of a solar cell being manufactured according to another embodiment of the present invention. FIG. 6 is a cross-sectional view of a solar cell being manufactured according to another embodiment of the present invention. FIG. 6 is a cross-sectional view of a solar cell being manufactured according to another embodiment of the present invention.

  The following detailed description is merely exemplary in nature and is not intended to limit the embodiments of the present subject matter or the application and uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration”. Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. A method for manufacturing a solar cell is disclosed. The method includes providing a silicon substrate having a thin dielectric layer on the back surface, and a silicon layer deposited on the thin dielectric layer, and forming a layer of doping material on the deposited silicon layer. Forming an oxide layer over the layer of doping material, partially removing the oxide layer, the layer of doping material and the deposited silicon layer into an interdigitated pattern, and raising the temperature The dopant is transferred from the layer of doped material to the deposited silicon layer and simultaneously grown on the deposited silicon layer to grow an oxide layer and form a doped crystallized polysilicon layer. Doping with a dopant from a layer of doping material, depositing a doped wide bandgap semiconductor and antireflective coating on the back surface of the solar cell, On the front side of the battery, including the method comprising depositing a wide band gap semiconductor and antireflective coatings doped, the.

  Another method of manufacturing a solar cell is disclosed. The method includes providing a silicon substrate having a thin dielectric layer on the back surface and a silicon layer deposited on the thin dielectric layer, and forming a layer of doping material on the deposited silicon layer; Forming an oxide layer on the layer of doping material, partially removing the oxide layer, the layer of doping material and the deposited silicon layer in a cross-finger pattern, and a textured silicon region To etch the exposed silicon substrate, to raise the temperature and to transfer the dopant from the layer of doping material to the deposited silicon layer, while at the same time growing the oxide layer, In order to form a polysilicon layer, the deposited silicon layer is doped with a dopant from a layer of doping material, and on the back surface of the solar cell, Coating a thick first layer of anti-reflective wide bandgap amorphous silicon and an anti-reflective coating, and coating a thin second layer of anti-reflective coating of wide band-gap amorphous silicon doped on the front surface of the solar cell. The thin layer is 10% to less than 30% of the thickness of the thick layer.

  Yet another method of manufacturing a solar cell is disclosed. The method comprises providing a silicon substrate having a thin dielectric layer on a back surface and a doped silicon layer on the thin dielectric layer, forming an oxide layer on the doped silicon layer, and crossing fingers. Growing a silicon oxide layer on the backside of the solar cell by partially removing the oxide layer and the doped silicon layer in a mold pattern and heating the silicon substrate in an oxygen-supplied environment Crystallizing the silicon layer to form a doped polysilicon layer, depositing a doped wide bandgap semiconductor on the back surface of the solar cell, and on the front surface of the solar cell. Depositing a wide band gap semiconductor doped with and an antireflective coating.

  Yet another method of manufacturing a solar cell is disclosed. The method comprises providing a silicon substrate having a thin dielectric layer on a back surface and a doped silicon layer on the thin dielectric layer, forming an oxide layer on the doped silicon layer, and crossing fingers. In a mold pattern, the oxide layer and the doped silicon layer are partially removed, the exposed silicon substrate is etched to form a textured silicon region, and the silicon is supplied in an oxygen-supplied environment. Growing a silicon oxide layer on the back surface of the solar cell by heating the substrate, crystallizing the silicon layer to form a doped polysilicon layer, and on the back surface of the solar cell; Deposit doped wide bandgap amorphous silicon and anti-reflective coating, and dopin on front of solar cell It includes forming a film of a wide band gap of amorphous silicon and anti-reflective coating that is, a.

  Yet another embodiment of a method for manufacturing a solar cell is disclosed. The method includes providing a silicon substrate having a thin dielectric layer on a back surface and a doped silicon layer on the thin dielectric layer, forming an oxide layer on the doped silicon layer, In a pattern, partially removing the oxide layer and doped silicon layer, etching the exposed silicon substrate to form a textured silicon region, and a silicon substrate in an oxygen supplied environment A silicon oxide layer is grown on the back surface of the solar cell by crystallizing the silicon layer to crystallize to form a doped polysilicon layer; and on the front and back surfaces of the solar cell. A wide bandgap amorphous silicon and an anti-reflective coating simultaneously doped with Partially removing the doped wide bandgap semiconductor and oxide layer to form a first aperture, a first metal grid electrically coupled to the doped polysilicon layer, and a solar Simultaneously forming a second metal grid electrically coupled to the emitter region on the backside of the battery.

  An improved technique for manufacturing solar cells is to provide a thin dielectric layer and a deposited silicon layer on the backside of the silicon substrate. A region of doped polysilicon can be formed by transferring a dopant to the deposited silicon layer or by in situ formation of the doped polysilicon region. An oxide layer and a doped wide bandgap semiconductor layer may be formed following the front and back surfaces of the solar cell. One variation involves texturing the front and back surfaces prior to oxide formation and doped wide bandgap semiconductor formation. Contact holes can be subsequently formed through the upper layer to expose the doped polysilicon region. A metallization process can subsequently be performed to form contacts on the doped polysilicon layer. A second group of contacts is also formed by connecting the metal directly to the emitter region of the silicon substrate formed by a wide bandgap semiconductor layer disposed between regions of doped polysilicon on the back surface of the solar cell. Can be done.

  Various tasks performed in connection with the manufacturing process are illustrated in FIGS. Also, some of the various tasks need not be performed in the order illustrated, and may be incorporated into a more comprehensive procedure, process, or manufacturing with additional functionality not described in detail herein.

  1-3 illustrate an embodiment of manufacturing a solar cell 100 that includes a silicon substrate 102, a thin dielectric layer 106, and a deposited silicon layer 104. In some embodiments, the silicon substrate 102 can be cleaned, polished, planarized and / or thinned or otherwise processed prior to the formation of the thin dielectric layer 106. The thin dielectric layer 106 and the deposited silicon layer 104 can be grown by a thermal process. A layer of doping material 108 followed by a first oxide layer 110 can be deposited on the deposited silicon layer 104 by a conventional deposition process. The layer of doping material 108 can include, but is not limited to, a doping material, ie, a layer of positive doping material such as dopant 109, eg, boron, or a negative doping material such as phosphorus. The thin dielectric layer 106 and the deposited silicon layer 104 are each described as being grown by a thermal process or deposited by a conventional deposition process, but any other described or listed herein. As with the formation, deposition or growth process steps, each layer or material can be formed using any suitable process. For example, forming a chemical vapor deposition (CVD) process, low pressure CVD (LPCVD), atmospheric pressure CVD (APCVD), plasma CVD (PECVD), thermal growth, sputtering as well as any other desired technique is described. It can be used in places where Thus, similarly, the doping material 108 can be formed on the substrate by a deposition technique, sputtering, or a printing process such as ink jet printing or screen printing.

  FIG. 4 shows the same solar cell 100 as FIGS. 1-3 after performing a material removal process and forming an exposed polysilicon region 124. Some examples of material removal processes include mask and etch processes, laser ablation processes, and other similar techniques. The exposed polysilicon region 124 and the layer 108 of doping material can be formed in any desired shape including an interdigitated pattern. If a masking process is used, the process can be performed using a screen printer or an ink jet printer to apply the mask ink with a predetermined interdigitated pattern. Thus, conventional chemical wet etching techniques can be used to remove the mask ink that results in the interdigitated pattern of the exposed polysilicon region 124 and the layer 108 of doping material. In at least one embodiment, some or all of the first oxide layer 110 may be removed. As shown in FIGS. 4 and 5, the removal of this oxide layer 110 can be accomplished with the same etching or ablation process in which regions of the deposited silicon layer 104 and dielectric layer 106 are removed.

  Referring to FIG. 5, the solar cell 100 is subjected to a second etching process, resulting in etching of the exposed polysilicon region 124, and the first textured silicon on the back surface of the solar cell to increase the concentration of solar radiation. Region 130 and a second textured silicon region 132 in front of the solar cell can be formed. The textured surface can have a regular or irregularly shaped surface that scatters incident light and reduces the amount of light reflected back from the surface of the solar cell.

  Referring to FIG. 6, the solar cell 100 can be heated 140 to move the doping material 109 from the doping material layer 108 to the deposited silicon layer 104. The same heating 140 can also form a silicon oxide or second oxide layer 112 on the layer 108 of doping material and the first textured silicon region 130. During this process, a third oxide layer can be grown 114 on the second textured silicon region 132. Either oxide layer 112, 114 may comprise a high quality oxide. High quality oxides are low interface state density oxides typically grown by thermal oxidation at temperatures in excess of 900 degrees Celsius that can provide improved passivation.

  Accordingly, referring to FIG. 7, the deposited silicon layer 104 can be doped with the doping material 109 from the layer 108 of dopant material to form a doped polysilicon layer 150. In one embodiment, the formation of a doped polysilicon layer is achieved by growing the oxide layer while simultaneously raising the temperature and transferring the dopant 109 from the layer 108 of doped material to the deposited silicon layer 104. Can be done. Doping the deposited silicon layer 104 with the dopant 109 from the layer of doping material 108 forms a doped crystallized polysilicon layer or doped polysilicon layer 150. In one of several embodiments, if a positive doping material is used, doped polysilicon layer 150 may include a layer of positively doped polysilicon. In the illustrated embodiment, the silicon substrate 102 comprises a bulk N-type silicon substrate. In some embodiments, if a negative doping material is used, doped polysilicon layer 150 may include a layer of negatively doped polysilicon. In one embodiment, the silicon substrate 102 must include a bulk P-type silicon substrate.

  Referring to FIG. 8, a doped first wide band gap semiconductor layer 160 may be deposited on the back surface of the solar cell 100. In one embodiment, the doped first wide bandgap semiconductor layer 160 is partially conductive with a resistance of at least 10 Ω · cm. In the same embodiment, the doped first wide bandgap semiconductor layer 160 has a bandgap greater than 1.05 electron volts (eV), by the first textured silicon region 130 and by the second oxide layer 112. It can act as a heterojunction in the area on the backside of the already coated solar cell. Examples of doped wide bandgap semiconductors include silicon carbide and aluminum gallium nitride. Any other doped wide bandgap semiconductor material that exhibits the above properties and characteristics can be used as well. The doped first wide bandgap semiconductor layer 160 may be composed of a thick doped first wide bandgap amorphous silicon layer.

  Referring to FIG. 9, a doped second wide bandgap semiconductor 162 may be deposited on the second textured silicon region 132 on the front surface of the solar cell 100. In one embodiment, both the doped wide bandgap semiconductor layers 160, 162 on the back and front surfaces of the solar cell 100 can comprise doped wide bandgap negative semiconductors. In another embodiment, the doped second wide bandgap semiconductor 162 can be relatively thin compared to the doped thick first wide bandgap semiconductor layer. Thus, in some embodiments, the doped thin second wide bandgap semiconductor layer can comprise a thickness of 10% to 30% of the doped thick first wide bandgap semiconductor layer. In yet another embodiment, the doped wide bandgap semiconductor layers 160, 162 on the back and front surfaces of the solar cell are both doped wide bandgap negative semiconductors or doped wide bandgap positive types, respectively. Semiconductors can be included. Subsequently, an anti-reflective coating (ARC) 170 may be deposited on the doped second wide band gap semiconductor 162 in the same process. In another embodiment, the anti-reflective coating 170 can be deposited on the doped first wide band gap semiconductor 160 in the same process. In some embodiments, ARC 170 may be composed of silicon nitride.

  FIG. 10 illustrates a partial view of a doped first wide bandgap semiconductor 160, a second oxide layer 112, and a layer of doping material 108 on the back surface of the solar cell 100 to form a series of contact openings 180. Indicates removal. In one embodiment, the removal technique can be achieved using an ablation process. One such ablation process is a laser ablation process. In another embodiment, the removal technique can be any conventional etching process, such as screen printing or inkjet printing of a mask followed by an etching process.

  Referring to FIG. 11, a first metal grid or grid line 190 may be formed on the back surface of the solar cell 100. The first metal grid line 190 can be electrically coupled to the doped polysilicon 150 in the contact opening 180. In one embodiment, a first metal grid line 190 is formed in the doped first wide bandgap semiconductor 160, the second oxide layer 112, and the layer of doping material 108 through the contact opening 180 and from the solar cell. The positive electrical terminal of the external electrical circuit to be powered can be connected.

  Referring to FIG. 12, a second metal grid or grid line 192 may be formed on the back surface of the solar cell 100. Second metal grid line 192 is electrically coupled to second textured silicon region 132. In one embodiment, the second metal grid line 192 is doped with a first doped wide bandgap semiconductor 160, a second oxide layer 112, and a first textured silicon region that act as a heterojunction in an area on the back surface of the solar cell. 130 and can be connected to the negative electrical terminal of an external electrical circuit powered by the solar cell. In some embodiments, the formation of the metal grid lines referenced in FIGS. 11 and 12 can be performed by electroplating processes, screen printing processes, ink jet processes, plating on metals formed from aluminum metal nanoparticles, or any It can be performed by other metallization or metal forming process steps.

  13 to 18 show another embodiment for manufacturing the solar cell 200. Unless otherwise specified below, the numerical displays used to represent components in FIGS. 13-18 are the same as those shown in FIGS. 1-12 above, except that the number displayed is increased by 100. It is similar to the display of numbers used to represent features.

  Referring to FIGS. 13-14, another embodiment for manufacturing a solar cell 200 forms a first oxide layer 210, a thin dielectric layer 206, a doped polysilicon layer 250 on a silicon substrate 202. Can include. The silicon substrate 202 can be cleaned, polished, planarized and / or thinned or otherwise processed prior to the formation of the thin dielectric layer 206, as described above. The first oxide layer 210, the dielectric layer 206, and the doped polysilicon layer 250 can be grown by a thermal process. In one embodiment, the doped silicon layer is crystallized and doped by growing a silicon oxide layer or oxide layer 210 on the back surface of the solar cell by heating the silicon substrate 202 in an oxygenated environment. A polysilicon layer 250 is formed. In another embodiment, growing the doped polysilicon layer 250 on the dielectric layer 206 includes growing a positively doped polysilicon, such as a boron dopant or the like. Of the doping material 209. In another embodiment, negatively doped polysilicon can be used. The thin dielectric layer 206 and the doped polysilicon layer 250 are each described as being grown by a thermal process or deposited by a conventional deposition process, but as described above, are described or listed herein. As with any other formation, deposition or growth process step, each layer or material can be formed using any suitable process.

  The solar cell 200 is further processed by partially removing the first oxide layer 210, the doped polysilicon layer 250, and the dielectric layer 206, and using an interdigitated pattern using conventional masking and etching processes. Thus, the exposed region 220 of the silicon substrate can be exposed. If conventional masking and etching processes are used, an ablation process can be used. If an ablation process is used, the first oxide layer 210 may be left partially intact on the doped polysilicon layer 250, as shown in FIG. In another embodiment, screen printing or inkjet printing techniques combined with an etching process can be used. In such embodiments, the first oxide layer 210 can be etched away from the doped polysilicon layer 250.

  Referring to FIG. 15, a first textured silicon surface 230 and a second texturing for simultaneously etching the exposed silicon substrate 220 and the exposed area on the front surface of the solar cell 200 to increase the concentration of solar radiation. A silicon surface 232 can be formed.

  Referring to FIG. 16, the solar cell 200 can be heated 240 to a temperature exceeding 900 degrees Celsius while the second oxide layer 212 is formed on the back surface and the third oxide layer 214 is formed on the front surface of the solar cell 200. In another embodiment, both oxide layers 212, 214 can include high quality oxide, as described above.

  Referring to FIG. 17, a doped first wide band gap semiconductor layer 260 may be simultaneously formed on the back surface and the front surface of the solar cell. The doped first wide bandgap semiconductor layer 260 may be partially conductive with a resistance greater than 10 Ω · cm. The doped first wide band gap semiconductor layer 260 may also have a band gap greater than 1.05 eV. In addition, the first wide band gap semiconductor layer can act as a heterojunction in the area of the back surface of the solar cell that covers the first textured silicon region 230 and the second oxide layer 212.

  The doped first wide bandgap semiconductor layer 260 may be 10% to 30% thicker than the doped second wide bandgap semiconductor layer 262. In other embodiments, the thickness can be varied by less than 10% or more than 30% without departing from the techniques described herein. Both doped wide bandgap semiconductor layers 260, 262 can be positively doped semiconductors. It should be noted that in other embodiments having different substrates and polysilicon doped polarities, negatively doped wide bandgap semiconductor layers can be used as well. Subsequently, an anti-reflective coating (ARC) 270 may be deposited on the doped second wide band gap semiconductor 262. In one embodiment, the antireflective coating 270 can be comprised of silicon nitride. In some embodiments, the ARC can also be deposited on the doped first wide bandgap semiconductor layer 260.

  Referring to FIG. 18, the doped first wide bandgap semiconductor layer 260 and the second oxide layer 212 are partially removed on the doped polysilicon layer 250, referring to FIGS. A series of contact openings similar to those described above can be formed with similar molding techniques. Subsequently, a first metal grid line 290 can be formed on the back surface of the solar cell 200, and the first metal grid line 290 can be electrically coupled to the doped polysilicon 250 within the contact opening. it can. A second metal grid line 292 may be formed on the back surface of the solar cell 200, and the second metal grid line 292 is electrically coupled to the first textured silicon region or N-type emitter region 230. In one embodiment, both the first and second metal grid lines can be formed simultaneously. Next, additional contacts can be made to the first and second metal grid lines 290, 292 by other components of the energy system incorporating the solar cell 200.

While at least one exemplary embodiment has been presented in the detailed description above, it should be appreciated that a vast number of variations exist. It should also be recognized that the exemplary embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter. Rather, the above-described modes for carrying out the invention provide those skilled in the art with simple guidelines for practicing the described embodiments. There are various functions and arrangements of elements without departing from the scope defined by the claims, including known equivalents and foreseeable equivalents, as of the filing of this patent application. It should be understood that changes can be made.
(Item 1)
A method of manufacturing a solar cell including a silicon substrate, the silicon substrate having a front surface facing the sun during normal operation and a back surface opposite to the front surface,
The above method
Providing a silicon substrate having a thin dielectric layer on the back surface and a silicon layer deposited on the thin dielectric layer;
Forming a layer of doping material on the deposited silicon layer;
Forming an oxide layer on the layer of doping material;
Partially removing the oxide layer, the layer of doping material, and the deposited silicon layer into an interdigitated pattern;
Growing the oxide layer at the same time as raising the temperature to transfer the dopant from the layer of doping material to the deposited silicon layer;
Doping the deposited silicon layer with a dopant from the layer of doping material to form a doped crystallized polysilicon layer;
Depositing a doped wide bandgap semiconductor and an antireflective coating on the back surface of the solar cell;
Depositing a doped wide bandgap semiconductor and an anti-reflective coating on the front surface of the solar cell.
(Item 2)
The method of item 1, wherein preparing the silicon substrate comprises preparing a silicon substrate of N-type bulk silicon.
(Item 3)
The method of item 1, wherein providing the silicon substrate comprises providing a silicon substrate of P-type bulk silicon.
(Item 4)
2. The method of item 1, wherein forming a layer of doping material on the deposited silicon layer comprises forming a layer of positive doping material on the deposited silicon layer.
(Item 5)
The method of item 1, wherein forming the layer of doping material on the deposited silicon layer comprises forming a layer of negative doping material on the deposited silicon layer.
(Item 6)
The method of item 1, wherein depositing the doped wide bandgap semiconductor comprises depositing a doped wide bandgap amorphous silicon.
(Item 7)
The method of item 1, wherein depositing the doped wide bandgap semiconductor comprises depositing a semiconductor having a bandgap greater than 1.05 electron volts.
(Item 8)
The oxide layer, the doping material layer, and the deposited silicon layer may be partially removed in an interdigitated pattern to remove the oxide layer, the doping material layer, and the deposited silicon layer. 2. The method of item 1, comprising using an etching process to remove.
(Item 9)
Removing the oxide layer, the layer of doping material, and the deposited silicon layer partially into the interdigitated pattern may include removing the oxide layer, the layer of doping material, and the deposited silicon. The method of item 1, comprising using an ablation process to remove the layer.
(Item 10)
The method of item 1, wherein depositing an anti-reflective coating on the front surface of the solar cell comprises depositing silicon nitride.
(Item 11)
A method of manufacturing a solar cell comprising a silicon substrate, wherein the silicon substrate has a front surface facing the sun during normal operation and a back surface opposite to the front surface,
The above method
Providing a silicon substrate having a thin dielectric layer on the back surface and a doped silicon layer on the thin dielectric layer;
Forming an oxide layer on the doped silicon layer;
Partially removing the oxide layer and the doped silicon layer into an interdigitated pattern;
Etching the exposed silicon substrate to form a textured silicon region;
The silicon substrate is heated in an environment supplied with oxygen to grow a silicon oxide layer on the back surface of the solar cell, wherein the doped silicon layer is crystallized to form a doped polycrystal. Forming a silicon layer;
Simultaneously depositing a doped wide bandgap amorphous silicon and an anti-reflective coating on the front and back surfaces of the solar cell;
Partially removing the antireflective coating, the doped wide bandgap amorphous silicon, and the oxide layer to form a series of contact openings;
Forming simultaneously a first metal grid electrically coupled to the doped polysilicon and a second metal grid electrically coupled to a portion of the interdigitated pattern on the back surface of the solar cell; And a method comprising:
(Item 12)
Item 12. The method of item 11, wherein the doped polysilicon layer comprises a layer of negatively doped polysilicon.
(Item 13)
Item 12. The method of item 11, wherein the doped polysilicon layer comprises a layer of positively doped polysilicon.
(Item 14)
12. The method of item 11, wherein depositing an anti-reflective coating on the front and back surfaces of the solar cell comprises depositing silicon nitride on the back and front surfaces of the solar cell.
(Item 15)
A method of manufacturing a solar cell comprising a silicon substrate, wherein the silicon substrate has a front surface facing the sun during normal operation and a back surface opposite to the front surface,
The above method
Providing a silicon substrate having a thin dielectric layer on the back surface and a silicon layer doped on the thin dielectric layer;
Forming an oxide layer on the doped silicon layer;
Partially removing the oxide layer and the doped silicon layer into an interdigitated pattern;
Etching the exposed silicon substrate to form a textured silicon region;
The silicon substrate is heated in an environment supplied with oxygen to grow a silicon oxide layer on the back surface of the solar cell, and the silicon layer is crystallized to form a doped polysilicon layer. Forming,
Depositing a doped wide bandgap amorphous silicon and antireflective coating on the back surface of the solar cell;
Depositing a doped wide bandgap amorphous silicon and antireflective coating on the front surface of the solar cell.
(Item 16)
16. The method of item 15, wherein the doped polysilicon layer comprises phosphorus.
(Item 17)
16. A method according to item 15, wherein the doped polysilicon layer comprises boron.
(Item 18)
A method of manufacturing a solar cell comprising a silicon substrate, wherein the silicon substrate has a front surface facing the sun during normal operation and a back surface opposite to the front surface,
The above method
Providing a silicon substrate having a thin dielectric layer on the back surface and a doped silicon layer on the thin dielectric layer;
Forming an oxide layer on the doped silicon layer;
Partially removing the oxide layer and the doped silicon layer into an interdigitated pattern;
The silicon substrate is heated in an environment supplied with oxygen to grow a silicon oxide layer on the back surface of the solar cell, and the silicon layer is crystallized to form a doped polysilicon layer. Forming,
Depositing a doped wide band gap semiconductor on the back surface of the solar cell;
Depositing a doped wide bandgap semiconductor and an anti-reflective coating on the front surface of the solar cell.
(Item 19)
19. The method of item 18, wherein preparing the silicon substrate comprises preparing an N-type bulk silicon silicon substrate.
(Item 20)
19. The method of item 18, wherein preparing the silicon substrate comprises preparing a silicon substrate of P-type bulk silicon.

Claims (20)

  A solar cell,
  A silicon substrate;
  A first emitter region disposed on a surface of the silicon substrate, the first emitter region comprising a doped wide bandgap semiconductor layer of a first conductivity type;
  A second emitter region disposed on the surface of the silicon substrate, the second emitter region having a doped crystalline silicon layer of a second conductivity type disposed on a thin dielectric layer;
  First and second contacts disposed on the first emitter region and the second emitter region, respectively, and electrically connected to the first emitter region and the second emitter region, respectively.
  Solar cell.   The layer of the doped wide bandgap semiconductor further extends over a portion of the second emitter region.
  The solar cell according to claim 1.   A material layer disposed between the doped crystalline silicon layer and the portion of the doped wide bandgap semiconductor extending above the portion of the second emitter region;
  The material layer includes the dopant of the second conductivity type.
  The solar cell according to claim 2.   The dopant of the second conductivity type is a phosphorus dopant.
  The solar cell according to claim 3.   The dopant of the second conductivity type is a boron dopant.
  The solar cell according to claim 3.   The doped wide bandgap semiconductor is disposed on a second thin dielectric layer
  The solar cell according to any one of claims 1 to 5.   The silicon substrate is N-type bulk silicon
  The solar cell according to any one of claims 1 to 6.   And further comprising an anti-reflective coating on the doped wide bandgap semiconductor in the first emitter region.
  The solar cell according to any one of claims 1 to 7.   The antireflective coating comprises silicon nitride
  The solar cell according to claim 8.   And further comprising a second layer of the doped wide bandgap semiconductor disposed proximate to a second surface of the silicon substrate opposite the surface of the silicon substrate.
  The solar cell according to any one of claims 1 to 9.   Further comprising an antireflective coating on the second layer of the doped wide bandgap semiconductor.
  The solar cell according to claim 10.   The doped wide band gap semiconductor has a band gap greater than 1.05 electron volts (eV).
  The solar cell according to any one of claims 1 to 11.   The doped wide bandgap semiconductor has a resistance greater than 10 Ω · cm
  The solar cell according to any one of claims 1 to 12.   The surface of the silicon substrate has a textured trench, and the doped wide bandgap semiconductor is formed in the textured trench.
  The solar cell according to any one of claims 1 to 13.   A solar cell,
  A crystalline silicon substrate;
  A first emitter region disposed on a surface of the crystalline silicon substrate, the first emitter region having a layer of a doped negative wide bandgap semiconductor, the doped negative wide A first emitter region having a band gap greater than 1.05 electron volts (eV) and a resistance greater than 10 Ω · cm;
  A second emitter region disposed on the surface of the crystalline silicon substrate, the second emitter region comprising a doped positive crystalline silicon layer disposed on a thin dielectric layer; The layer of doped negative wide bandgap semiconductor further includes a second emitter region extending above a portion of the second emitter region;
  First and second contacts disposed on the first emitter region and the second emitter region, respectively, and electrically connected to the first emitter region and the second emitter region, respectively.
  Solar cell.   The doped negative wide bandgap semiconductor is disposed on a second thin dielectric layer
  The solar cell according to claim 15.   The surface of the crystalline silicon substrate has a textured trench, and the doped negative wide bandgap semiconductor is formed in the textured trench.
  The solar cell according to claim 15 or 16.   A solar cell,
  A crystalline silicon substrate;
  A first emitter region disposed on a surface of the crystalline silicon substrate, the first emitter region comprising a doped positive wide bandgap semiconductor layer, the doped positive wide A first emitter region having a band gap greater than 1.05 electron volts (eV) and a resistance greater than 10 Ω · cm;
  A second emitter region disposed on the surface of the crystalline silicon substrate, the second emitter region having a doped negative crystalline silicon layer disposed on a thin dielectric layer; The layer of doped positive-type wide bandgap semiconductor further includes a second emitter region extending above a portion of the second emitter region;
  First and second contacts disposed on the first emitter region and the second emitter region, respectively, and electrically connected to the first emitter region and the second emitter region, respectively.
  Solar cell.   The doped positive wide bandgap semiconductor is disposed on a second thin dielectric layer.
  The solar cell according to claim 18.   The surface of the crystalline silicon substrate has a textured trench, and the doped positive wide bandgap semiconductor is formed in the textured trench.
  The solar cell according to claim 18 or 19.