Abstract: A new solar cell comprising a substrate, a VIB metal thin film deposited on the substrate, and a polycrystalline III-V semiconductor thin film deposited on the VIB metal thin film. A method of making a solar cell comprising providing a substrate, depositing a VIB metal thin film on the substrate, and depositing a polycrystalline III-V semiconductor thin film on the VIB metal thin film. In one embodiment, a polycrystalline III-V semiconductor thin film comprising Indium Phosphide (InP) is deposited on a VIB metal thin film comprising Molybdenum (Mo) by Metal Organic Chemical Vapor Deposition (MOCVD). In another embodiment, growth of Indium phosphide (InP) crystals directly on metal foils is described using a method comprising a closed-spaced sublimation (CSS). In another embodiment, both InP nanowires and polycrystalline films were obtained by tuning growth conditions. In another embodiment, utilizing a silicon dioxide mask, selective nucleation of InP on metal substrates was obtained.

Abstract: A new solar cell is disclosed wherein the solar cell comprises a substrate, a VIB metal thin film deposited on the substrate, and a polycrystalline III-V semiconductor thin film deposited on the VIB metal thin film. A method of making the solar cell is described comprising providing a substrate, depositing a VIB metal thin film on the substrate, and depositing a polycrystalline III-V semiconductor thin film on the VIB metal thin film. In one embodiment a polycrystalline III-V semiconductor thin film comprising Indium Phosphide (InP) is deposited on a VIB metal thin film comprising Molybdenum (Mo) by Metal Organic Chemical Vapor Deposition (MOCVD).

Abstract: A solar concentrator is described. The solar concentrator includes a plane including a plurality of concentrating elements, wherein each concentrating element includes a hollow taper including a first opening; and at least one photoelectric conversion layer covering inner side surfaces of the concentrating elements.

Abstract: A thin film solar cell is disclosed comprising the following layers deposited on a substrate: a microcrystalline p- or n-layer, an intermediate microcrystalline silicon i-layer applied by a hot-wire chemical-vapor deposition (HWCVD) method on the microcrystalline p- or n-layer a), an additional i-layer of microcrystalline silicon, which is formed by depositing on the intermediate microcrystalline silicon i-layer, by a plasma enhanced chemical vapor deposition (PECVD), a sputtering process, or a photo-CVD method whereby layers b) and c) together form an i-layer, and if a p-layer is present as the layer of step a), an n-layer, and if an n-layer is present as the layer of step a), a p-layer that is either microcrystalline or amorphous.

Abstract: In one embodiment, a solar cell has base and emitter diffusion regions formed on the back side. The emitter diffusion region is configured to collect minority charge carriers in the solar cell, while the base diffusion region is configured to collect majority charge carriers. The emitter diffusion region may be a continuous region separating the base diffusion regions. Each of the base diffusion regions may have a reduced area to decrease minority charge carrier recombination losses without substantially increasing series resistance losses due to lateral flow of majority charge carriers. Each of the base diffusion regions may have a dot shape, for example.

Abstract: The disclosure provides a crystalline silicon solar cell wafer, and a solar cell employing the same. The crystalline silicon solar cell wafer, having an edge isolation structure, includes: a crystalline silicon substrate having a first surface, a second surface, and a side surface, and an insulating layer formed merely on the side surface of the crystalline silicon substrate.

Abstract: A method of manufacturing solar cells is disclosed. The method comprises depositing an etch-resistant dopant material on a silicon substrate, the etch-resistant dopant material comprising a dopant source, forming a cross-linked matrix in the etch-resistant dopant material using a non-thermal cure of the etch-resistant dopant material, and heating the silicon substrate and the etch-resistant dopant material to a temperature sufficient to cause the dopant source to diffuse into the silicon substrate.

Abstract: A thin film photovoltaic device on a substrate is being realized by a method for manufacturing a p-i-n junction semiconductor layer stack with a p-type microcrystalline silicon layer, a p-type amorphous silicon layer, a buffer silicon layer comprising preferably intrinsic amorphous silicon, an intrinsic type amorphous silicon layer, and an n-type silicon layer over the intrinsic type amorphous silicon layer.

Abstract: It is aimed to provide a photoelectric conversion device having high adhesion between a first semiconductor layer and an electrode layer as well as high photoelectric conversion efficiency. A photoelectric conversion device comprises an electrode layer, a first semiconductor layer located on the electrode layer and comprising a chalcopyrite-based compound semiconductor of group I-III-VI and oxygen, and a second semiconductor layer located on the first semiconductor layer and forming a pn junction with the first semiconductor layer. In the photoelectric conversion device, the first semiconductor layer has a higher molar concentration of oxygen in a part located on the electrode layer side with respect to a center portion in a lamination direction of the first semiconductor layer than a molar concentration of oxygen in the whole of the first semiconductor layer.

Abstract: A composition includes a chemical reaction product defining a first surface and a second surface, characterized in that the chemical reaction product includes a segregated phase domain structure including a plurality of domain structures, wherein at least one of the plurality of domain structures includes at least one domain that extends from a first surface of the chemical reaction product to a second surface of the chemical reaction product. The segregated phase domain structure includes a segregated phase domain array. The plurality of domain structures includes i) a copper rich. indium/gallium deficient Cu(In,Ga)Se2 domain and ii) a copper deficient, indium/gallium rich Cu(In,Ga)Se2 domain.

Abstract: A solar cell module includes a substrate, a lower electrode on the substrate, a light absorption layer on the lower electrode, an upper electrode on the light absorption layer, and a protective layer on the upper electrode, the protective layer extending along sidewalls of the light absorption layer to the lower electrode, the protective layer including a moisture absorbing material.

Abstract: A system and a process for forming a semi-conductor device, and solar cells (10) formed thereby. The process includes preparing a substrate (12) for deposition of a junction layer (14); forming the junction layer (14) on the substrate (12) using hot wire chemical vapor deposition; and, finishing the semi-conductor device.

Abstract: A method for forming a photovoltaic device includes patterning a dielectric layer on a substrate to form a patterned dielectric having local spacings between shapes and remote spacings between groups of shapes, and depositing a doped epitaxial layer over the patterned dielectric such that selective crystalline growth occurs in portions of the epitaxial layer in contact with the substrate and noncrystalline growth occurs in portions of the epitaxial layer in contact with the patterned dielectric. First metal contacts are formed over the local spacings of the patterned dielectric, and second metal contacts are formed over the remote spacings. Exposed portions of the noncrystalline growth are etched using the first and second metal contacts as an etch mask to form alternating interdigitated emitter and back contact stacks.

Abstract: One embodiment of the present invention provides a method for fabricating a solar cell. The method includes: melting a metallurgical-grade (MG) Si feedstock, lowering a single-crystalline Si seed to touch the surface of the molten MG-Si, slowly pulling out a single-crystal Si ingot of the molten MG-Si, processing the Si ingot into single crystal Si wafers to form MG-Si substrates for subsequent epitaxial growth, leaching out residual metal impurities in the MG-Si substrate, epitaxially growing a layer of single-crystal Si thin film doped with boron on the MG-Si substrate, doping phosphor to the single-crystal Si thin film to form an emitter layer, depositing an anti-reflection layer on top of the single-crystal Si thin film, and forming the front and the back electrical contacts.

Abstract: There is provided a hydrogen production device high in light use efficiency and capable of producing hydrogen with high efficiency. The hydrogen production device according to the present invention includes a photoelectric conversion part having a light acceptance surface and a back surface, a first gas generation part provided on the back surface, and a second gas generation part provided on the back surface, in which one of the first gas generation part and the second gas generation part is a hydrogen generation part to generate H2 from an electrolytic solution, another one thereof is an oxygen generation part to generate O2 from the electrolytic solution, the first gas generation part is electrically connected to the back surface, and the second gas generation part is electrically connected to the light acceptance surface via a first conductive part.

Abstract: A solar cell is discussed. The solar cell includes a substrate having a first conductivity type and made of a crystalline semiconductor; an emitter region having a second conductivity type opposite the first conductivity type, and forming a p-n junction with the substrate; a surface field region having the first conductivity type and being separated from the emitter region; a first electrode connected to the emitter region; and a second electrode connected to the surface field region, wherein at least one of the emitter region and the surface field region includes a plurality of semiconductor portions, and at least one of the plurality of semiconductor portion is a crystalline semiconductor portion.

Abstract: A photovoltaic device is described. The photovoltaic device comprises an organic-based antireflection layer. A method of making a photovoltaic device is also described.

Abstract: It is an object of the present invention to improve photoelectric conversion efficiency in a photoelectric conversion device. The photoelectric conversion device according to the present invention uses a polycrystalline semiconductor layer including a plurality of semiconductor particles coupled together as a light-absorbing layer, each of the semiconductor particles including a group I-III-VI compound, each of the semiconductor particles having a higher composition ratio PI of a group I-B element to a group III-B element in a surface portion thereof than that in a central portion thereof.

Abstract: Methods for forming a photovoltaic device include depositing a p-type layer on a substrate and cleaning the p-type layer by exposing a surface of the p-type layer to a plasma treatment to react with contaminants. An intrinsic layer is formed on the p-type layer, and an n-type layer is formed on the intrinsic layer.

Abstract: This invention relates to compounds and compositions used to prepare semiconductor and optoelectronic materials and devices. This invention provides a range of compounds, compositions, materials and methods directed ultimately toward photovoltaic applications, as well as devices and systems for energy conversion, including solar cells. In particular, this invention relates to molecular precursor compounds and precursor materials for preparing photovoltaic layers.

Abstract: A flexible solar cell assembly may include a lower glass layer, a lower polyvinyl butyral (PVB) layer, a translucent flexible thin film solar cell, an upper polyvinyl butyral (PVB) layer, an upper glass layer consecutively laminated and closely connected from top to bottom. wherein the translucent flexible thin film solar cell is an amorphous silicon flexible thin film solar cell or an organic flexible thin film solar cell.

Abstract: In one aspect, optoelectronic devices are described herein. In some embodiments, an optoelectronic device comprises a fiber core, a radiation transmissive first electrode surrounding the fiber core, at least one photosensitive inorganic layer surrounding the first electrode and electrically connected to the first electrode, and a second electrode surrounding the inorganic layer and electrically connected to the inorganic layer. In some embodiments, the device comprises a photovoltaic cell.

Abstract: A photoelectric conversion element contains a transparent conductive film, a p-type amorphous silicon film, an i-type amorphous silicon film, an n-type single-crystal silicon substrate, an i-type amorphous silicon film, a p-type amorphous silicon film, a transparent conductive film, and a metallic film; and the film thickness of the transparent conductive film is greater than or equal to that of the transparent conductive film.

Abstract: Photovoltaic device with band-stop filter. The photovoltaic device includes an amorphous photovoltaic material and a band-stop filter structure having a stopband extending from a lower limiting angular frequency ?min?0 to an upper limiting angular frequency ?max where ?max>?min. The band-stop filter structure is arranged in the photovoltaic device relative to the photovoltaic material in order to attenuate electromagnetic radiations reaching the photovoltaic material with angular frequencies of ?* in the stopband, so that ?min<?*<?max. The angular frequencies ?* correspond to electronic excitations ??* from valence band tail (VBT) states of the amorphous photovoltaic material to conduction band tail (CBT) states of the amorphous photovoltaic material.

Abstract: The problem addressed by the present invention is providing a technique for fabricating, by a method simpler than conventional methods, a silicon substrate that is effective for light trapping, one surface of which has a textured structure and the other surface of which has higher reflectivity than the surface having the textured structure. The fabrication method for this semiconductor substrate comprises: a sandblasting step in which a first surface of a silicon substrate in an as-sliced state, fabricated by slicing a silicon ingot, is surface treated by sandblasting and, after the sandblasting step, a step for carrying out surface treatment using an etching solution that contains either or both of hydrofluoric acid and nitric acid on the silicon substrate.

Abstract: This invention relates to methods and articles using compounds, polymeric compounds, and compositions used to prepare semiconductor and optoelectronic materials and devices including thin film and band gap materials. This invention provides a range of compounds, polymeric compounds, compositions, materials and methods directed ultimately toward photovoltaic applications, transparent conductive materials, as well as devices and systems for energy conversion, including solar cells. In particular, this invention relates to polymeric precursor compounds and precursor materials for preparing photovoltaic layers. A compound may contain repeating units {MB(ER)(ER)} and {MA(ER)(ER)}, wherein MA is Ag, each MB is In or Ga, each E is S, Se, or Te, and each R is independently selected, for each occurrence, from alkyl, aryl, heteroaryl, alkenyl, amido, silyl, and inorganic and organic ligands.

Abstract: This invention includes processes for making a photovoltaic absorber layer having a predetermined stoichiometry on a substrate by depositing a precursor having the predetermined stoichiometry onto the substrate and converting the deposited precursor into a photovoltaic absorber material. This invention further includes processes for making a photovoltaic absorber layer having a predetermined stoichiometry on a substrate by (a) providing a polymeric precursor having the predetermined stoichiometry; (b) providing a substrate; (c) depositing the precursor onto the substrate; and (d) heating the substrate.

Abstract: This invention relates to methods for making materials using compounds, polymeric compounds, and compositions used to prepare semiconductor and optoelectronic materials and devices including thin film and band gap materials. This invention provides a range of compounds, polymeric compounds, compositions, materials and methods directed ultimately toward photovoltaic applications, transparent conductive materials, as well as devices and systems for energy conversion, including solar cells. This invention further relates to methods for making AIGS, AIS or AGS materials by providing one or more polymeric precursor compounds or inks thereof, providing a substrate, depositing the compounds or inks onto the substrate; and heating the substrate at a temperature of from about 20° C. to about 650° C.

Abstract: Provided is a method for manufacturing a semiconductor device. Also provided are: a semiconductor device which can be obtained by the method; and a dispersion that can be used in the method. A method for manufacturing a semiconductor device (500a) of the present invention comprises the steps (a)-(c) described below. (a) A dispersion which contains doped particles is applied to a specific part of a layer or a base. (b) An unsintered dopant implanted layer is obtained by drying the applied dispersion. (c) The specific part of the layer or the base is doped with a p-type or n-type dopant by irradiating the unsintered dopant implanted layer with light, and the unsintered dopant implanted layer is sintered, thereby obtaining a dopant implanted layer that is integrated with the layer or the base.

Abstract: A solid-state hole transport composite material (ssHTM) is provided made from a p-type organic semiconductor and a dopant material serving as a source for either sodium (Na+) or potassium (K+) ions. The p-type organic semiconductor may be molecular (a collection of discrete molecules, that are either chemically identical or different), oligomeric, polymeric materials, or combinations thereof. In one aspect, the p-type organic semiconductor is 2,2?,7,7?-tetrakis(N,N-di-p-methoxyphenylamine)-9,9?-spirobifluorene (Spiro-OMeTAD). The dopant material is an inorganic or organic material salt. A solid-state dye-sensitized solar cell (ssDSC) with the above-described ssHTM, is also provided.

Abstract: A method for manufacturing a photoelectric conversion device including a first-conductivity-type crystalline semiconductor region, an intrinsic crystalline semiconductor region, and a second-conductivity-type semiconductor region that are stacked over an electrode is provided for a new anti-reflection structure. An interface between the electrode and the first-conductivity-type crystalline semiconductor region is flat. The intrinsic crystalline semiconductor region includes a crystalline semiconductor region, and a plurality of whiskers that are provided over the crystalline semiconductor region and include a crystalline semiconductor. The first-conductivity-type crystalline semiconductor region and the intrinsic crystalline semiconductor region are formed by a low pressure chemical vapor deposition method at a temperature higher than 550° C. and lower than 650° C.

Abstract: A method for the fabrication of a three-dimensional thin-film semiconductor substrate with selective through-holes is provided. A porous semiconductor layer is conformally formed on a semiconductor template comprising a plurality of three-dimensional inverted pyramidal surface features defined by top surface areas aligned along a (100) crystallographic orientation plane of the semiconductor template and a plurality of inverted pyramidal cavities defined by sidewalls aligned along the (111) crystallographic orientation plane of the semiconductor template. An epitaxial semiconductor layer is conformally formed on the porous semiconductor layer. The epitaxial semiconductor layer is released from the semiconductor template. Through-holes are selectively formed in the epitaxial semiconductor layer with openings between the front and back lateral surface planes of the epitaxial semiconductor layer to form a partially transparent three-dimensional thin-film semiconductor substrate.

Abstract: This invention includes processes for making a photovoltaic absorber layer having a predetermined stoichiometry on a substrate by depositing a precursor having the predetermined stoichiometry onto the substrate and converting the deposited precursor into a photovoltaic absorber material. This invention further includes processes for making a photovoltaic absorber layer having a predetermined stoichiometry on a substrate by (a) providing a polymeric precursor having the predetermined stoichiometry; (b) providing a substrate; (c) depositing the precursor onto the substrate; and (d) heating the substrate.

Abstract: A method for manufacturing a silicon-based thin film solar cell including a crystalline silicon photoelectric conversion unit which contains a p-type layer (4p), a crystalline i-type silicon photoelectric conversion layer (4ic), and an n-type layer (4nc) stacked in this order from a transparent substrate side is provided. In one example, an n-type silicon-based thin film layer (4na) is formed on the crystalline i-type silicon photoelectric conversion layer (4ic), the n-type silicon-based thin film layer (4na) having an n-type silicon alloy layer having a film thickness of 1-12 nm and being in contact with the crystalline i-type silicon photoelectric conversion layer.

Abstract: A solar cell includes a crystalline Si layer including a pn junction and a semiconductor layer formed on a first main surface of the crystalline Si layer. The semiconductor layer has the same conductivity as a portion of the crystalline Si layer that is in contact with the semiconductor layer. The open circuit voltage under light irradiation onto the solar cell is different from a level difference between the quasi Fermi level of electrons and the quasi Fermi level of holes in the crystalline Si layer.

Abstract: A photovoltaic cell is fabricated onto a polyimide film using an unbalanced RF magnetron sputtering process. The sputtering process includes the addition of 0.05% to 0.5% oxygen to an inert gas stream. Portions of the photovoltaic cell are exposed to an elevated temperature CdCl2 treatment which is at or below the glass transition temperature of the polyimide film.

Abstract: The invention provides for a semiconductor wafer with a metal support element suitable for the formation of a flexible or sag tolerant photovoltaic cell. A method for forming a photovoltaic cell may comprise providing a semiconductor wafer have a thickness greater than 150 ?m, the wafer having a first surface and a second surface opposite the first and etching the semiconductor wafer a first time so that the first etching reduces the thickness of the semiconductor wafer to less than 150 ?m. After the wafer has been etched a first time, a metal support element may be constructed on or over the first surface; and a photovoltaic cell may be fabricated, wherein the semiconductor wafer comprises the base of the photovoltaic cell.

Abstract: Disclosed is a photovoltaic device. The photovoltaic device includes: a first electrode and a second electrode; a first unit cell and a second unit cell which are placed between the first electrode and the second electrode and include a first conductive semiconductor layer, an intrinsic semiconductor layer and a second conductive semiconductor layer; and an intermediate reflector which is placed between the first unit cell and the second unit cell, and includes a hydrogenated amorphous carbon layer.

Abstract: Methods of forming contacts for back-contact solar cells are described. In one embodiment, a method includes forming a thin dielectric layer on a substrate, forming a polysilicon layer on the thin dielectric layer, forming and patterning a solid-state p-type dopant source on the polysilicon layer, forming an n-type dopant source layer over exposed regions of the polysilicon layer and over a plurality of regions of the solid-state p-type dopant source, and heating the substrate to provide a plurality of n-type doped polysilicon regions among a plurality of p-type doped polysilicon regions.

Abstract: In order to improve a thin film solar cell with an amorphous silicon absorber layer being in single or in tandem configuration, the addressed absorber layer of a-Si:H is manufactured by plasma enhanced vapor deposition in an RF-SiH4 plasma, wherein the deposition is performed at at least one of at the process pressure below 0.5 mbar and of at an RF power density below 370 W/14000 cm2.

Abstract: Methods for improving the efficiency of solar cells, and a solar cell thereof. One aspect involves a solar cell with a semiconductor layer (11, 12, 13, 14, 15, 16, 17) with a natural band gap NB (NB2, NB3, NB4, NB5, NB6, NB7). This semiconductor layer also has at least one electrode (100, 101, 110, 111, 120, 121) designed to produce an ambient voltage V (V1, V2, V3, V4, V5, V6, V7) into the layer. The incoming photons therefore experience a modified NB?V=B band gap (B1, B2, B3, B4, B5, B6, B7), referred here to as the apparent band gap. Photons with E>B1 will be absorbed into the band gap B, and the electron in the semiconductor valence band will get excited onto the conduction band thus resulting in photocurrent. The ability to tune the apparent band gap B provides an enormous strength to optimize the incoming photon collection.

Abstract: A large surface area photovoltaic device having high conversion efficiency and excellent mass productivity is provided. A photovoltaic device 100 having a photovoltaic layer 3 comprising a crystalline silicon layer formed on a substrate 1, wherein the crystalline silicon layer has a crystalline silicon i-layer 42, and the crystalline silicon i-layer 42 has a substrate in-plane distribution represented by an average value for the Raman peak ratio, which represents the ratio of the Raman peak intensity for the crystalline silicon phase relative to the Raman peak intensity for the amorphous silicon phase, that is not less than 4 and not more than 8, a standard deviation for the Raman peak ratio that is not less than 1 and not more than 3, and a proportion of regions in which the Raman peak ratio is not more than 4 of not less than 0% and not more than 15%.

Abstract: A composite poly-silicon substrate for solar cell having a first substrate layer and a second substrate layer is disclosed. The purity of the first substrate layer ranges from 2N to 3N. The second substrate layer is formed on the first substrate layer, and the purity of the second substrate layer ranges from 6N to 9N.

Abstract: The present invention discloses a thin-film solar cell, which comprises an electrode layer and a semiconductor layer. The semiconductor layer comprises a P-type layer, an I-type layer and an N-type layer. The P-type layer is disposed on the electrode layer. The I-type layer comprises an I-type amorphous silicon layer and an I-type polymorphous silicon layer. The I-type amorphous silicon layer is disposed on the P-type layer. The I-type polymorphous silicon layer is disposed on the I-type amorphous silicon layer. The N-type layer is disposed on the I-type polymorphous silicon layer. Wherein, the I-type polymorphous silicon layer generates a crystalline diffraction event and reduces photolysis reaction for enhancing the conversion efficiency of the thin-film solar cell.

Abstract: An inexpensive polycrystalline silicon solar cell panel is provided by forming a polycrystalline silicon film in which pn junctions are formed by using fewer processes and in less time. Specifically, there is provided a manufacturing method for a polycrystalline silicon solar cell panel including: a process of forming an amorphous silicon film on a substrate surface using a vapor deposition method that uses an n-type or p-type doped vapor deposition material formed of silicon; a process of plasma-doping a surface layer of the amorphous silicon film with a p-type or n-type dopant; and a process of melting the amorphous silicon film by scanning the plasma-doped amorphous silicon film with plasma and performing re-crystallization.

Abstract: A photovoltaic device having n-i-p or p-i-n configuration is presented. The device includes a first semiconductor layer, a second semiconductor layer and an intrinsic layer interposed between the first semiconductor layer and the second semiconductor layer. The intrinsic layer includes cadmium, tellurium and oxygen. Method of making a photovoltaic device is also provided.

Abstract: A thin-film transistor according to the present disclosure is capable of balancing excellent on-characteristics and excellent off-characteristics, and in which the electrical characteristics are symmetric even when the source electrode and the drain electrode are switched. The thin-film transistor includes: a substrate; a gate electrode; a gate insulating layer; a crystalline silicon layer above the gate insulating layer above the gate electrode; a non-crystalline silicon layer above the gate insulating layer and on both sides of the crystalline silicon layer, having a thickness smaller than a thickness of the crystalline silicon layer; a channel protective layer above the crystalline silicon layer; and a source electrode and a drain electrode.

Abstract: A package structure and a solar cell with the same are provided. The package structure includes a transparent package bulk and at least one structure capable of changing a direction of light. The structure is disposed within the transparent package bulk and at a distance from a surface of the transparent package bulk. When applied to a solar cell, the package structure can reduce gridline shading.

Abstract: A wavelength conversion structure includes a light guide formed of a light-transmissive member having a laser light incident port that allows the laser light to be introduced and a phosphor-containing layer that covers at least part of the surface of the light guide. The light guide has a light diffusing structure having asperities and a light reflecting film. The asperities are formed over the surface of the light guide except a laser light incident surface having the laser light incident port. The light reflecting film is formed over the surface of the light guide along the asperities except the laser light incident port and the portion covered with the phosphor-containing layer.

Abstract: A method for manufacturing a solar cell according to an embodiment of the present invention includes preparing a semiconductor substrate having a first conductive type dopant; ion-implanting a pre-amorphization elements into a front surface of the semiconductor substrate to form an amorphous layer; and forming an emitter layer by ion-implanting second conductive type dopant into the front surface of the semiconductor substrate. The method then further includes heat-treating the layers to activate the second conductive type dopant. The method further includes forming a back surface field layer at a back surface of the semiconductor substrate by ion-implanting a first conductive type dopant.