JP2011522423A - Photovoltaic conductor: A composition containing submicron particles - Google Patents

Abstract

  Embodiments of the present invention relate to a silicon semiconductor device and a conductive thick film composition used in a solar cell device.

Description

  Embodiments described herein relate generally to a silicon semiconductor device and a conductive thick film composition used in a solar cell device.

  A conventional solar cell structure having a p-type base has a negative electrode that may be on the front side of the battery (also referred to as the solar side or the irradiation side) and a positive electrode that may be on the opposite side. The appropriate wavelength of radiation on the pn junction of the semiconductor body serves as an external energy source for generating hole-electron pairs in the body. Due to the potential difference present at the pn junction, the holes and electrons traverse the junction in opposite directions, thereby creating a current flow that can supply power to the external circuit. Most solar cells take the form of metallized (ie with conductive metal contacts) silicon wafers.

  There is a need for compositions, structures (eg, semiconductors, solar cells, or photodiode structures) with improved electrical performance, semiconductor devices (eg, semiconductors, solar cells, or photodiode devices), and methods of manufacturing the same.

  Embodiments of the invention include (a) one or more conductive materials, (b) one or more inorganic binders, (c) an organic vehicle in which 1-15% of the inorganic components are submicron particles, It relates to the composition containing this. In one embodiment, 85-99% of the inorganic components can have an average particle size d50 of 1.5-10 microns. In one embodiment, the one or more conductive materials may include silver. In one embodiment, the portion of silver includes submicron particles. In one embodiment, the submicron particles have an average particle size d50 of 0.1 to 1 micron. In one embodiment, the submicron particles have an average particle size d50 of 0.1 to 0.6 microns. In one embodiment, the particles have a bimodal particle size distribution.

  The composition comprises: (a) a metal selected from Zn, Pb, Bi, Gd, Ce, Zr, Ti, Mn, Sn, Ru, Co, Fe, Cu, Cr; (b) Zn, Pb, Bi, Gd A metal oxide of one or more metals selected from Ce, Zr, Ti, Mn, Sn, Ru, Co, Fe, Cu, Cr, and (c) a metal oxide of (b) when fired. One or more additives selected from the group consisting of any compound that can be produced, (d) mixtures thereof, may be included. In one embodiment, the additive may include ZnO or a compound that forms ZnO when fired. In one embodiment, the ZnO and / or inorganic binder may include submicron particles. ZnO may be 2-10 wt% of the total composition. The glass frit may be 1-6 wt% of the total composition. The conductive material may include Ag. Ag may be 90-99 wt% of the solids in the composition. In one embodiment, the inorganic component may be 70-95 wt% of the total composition.

  Another embodiment comprises (a) providing a semiconductor substrate, one or more insulating films, a thick film composition described herein, (b) applying an insulating film to the semiconductor substrate, (c) The present invention relates to a method for manufacturing a semiconductor device including a step of applying a thick film composition to an insulating film on a semiconductor substrate, and (d) a step of baking the semiconductor, the insulating film, and the thick film composition. In one aspect, the insulating film may include one or more components selected from titanium oxide, silicon nitride, SiNx: H, silicon oxide, silicon oxide / titanium oxide.

  Another embodiment relates to a semiconductor device manufactured by the method described herein. One aspect relates to a semiconductor device including an electrode that includes a composition described herein prior to firing. One embodiment relates to a solar cell including a semiconductor device.

  One embodiment relates to a semiconductor device including a semiconductor substrate, an insulating film, and a front-side electrode, wherein the front-side electrode includes one or more components selected from the group consisting of zinc silicate, zinc silicate or bismuth silicate.

It is a processing flow figure explaining manufacture of a semiconductor device.

Reference numerals shown in FIG. 1 will be described below.
10: p-type silicon substrate 20: n-type diffusion layer 30: silicon nitride film, titanium oxide film, or silicon oxide film 40: p ⁺ layer (back surface field: BSF (back surface field))
60: Aluminum paste formed on the back surface 61: Aluminum back electrode (obtained by baking the back surface aluminum paste)
70: Silver or silver / aluminum paste formed on the back side 71: Silver or silver / aluminum back electrode (obtained by firing the back silver paste)
500: Silver paste 501 formed on the front side according to the present invention 501: Silver front electrode according to the present invention (formed by firing the front side silver paste)

  There is a need for improved solar cells with improved efficiency. There is a need for a conductive composition suitable for forming narrow conductor wires having increased height. One aspect of the present invention relates to a composition comprising submicron particles. The composition may be a thick film composition. These compositions can be used to form solar cell electrodes. The electrode may be on the front side of the solar cell. In one embodiment, the electrode lines can be narrow and have an increased height.

  As used herein, “thick film composition” refers to a composition having a thickness of 1 to 100 microns when fired on a substrate. The thick film composition may include a conductive material, a glass composition, and an organic vehicle. The thick film composition may include additional components. As used herein, an additional component is referred to as an “additive”.

  The compositions described herein include one or more electrically functional materials and one or more glass frits dispersed in an organic medium. These compositions may be thick film compositions. The composition may also include one or more additives. Exemplary additives include metals, metal oxides, or any compound that can produce these metal oxides during firing.

  In one embodiment, the electrically functional powder may be a conductive powder. In one embodiment, a composition (eg, a conductive composition) can be used in a semiconductor device. In one aspect of this embodiment, the semiconductor device may be a solar cell or a photodiode. In another aspect of this embodiment, the semiconductor device may be one of a wide range of semiconductor devices. In one embodiment, the semiconductor device may be a solar cell.

  In one embodiment, the thick film compositions described herein can be used in solar cells. In one aspect of this embodiment, the solar cell efficiency may be higher than 70% of the reference solar cell. In another embodiment, the solar cell efficiency may be higher than 80% of the reference solar cell. Solar cell efficiency may be higher than 90% of the reference solar cell.

  In one embodiment, the ratio of the organic medium in the thick film composition to the inorganic components in the dispersion may depend on the paste application method determined by those skilled in the art and the type of organic medium used. In one embodiment, the dispersion may include 70-95 wt% inorganic components and 5-30 wt% organic medium (vehicle) to obtain good wettability.

  In one embodiment, some of the inorganic components may be submicron particles. In one aspect of this embodiment, the submicron particles can have an average particle size d50 of 0.1 to 1 micron. In another aspect, the submicron particles can have an average particle size d50 of 0.1 to 0.8 microns. In another aspect, the submicron particles can have an average particle size d50 of 0.2 to 0.6 microns.

  In one embodiment, the submicron particles may be 1-15 wt% of the composition. In another embodiment, the submicron particles may be 2-10 wt% of the composition. In another embodiment, the submicron particles may be 3-6 wt% of the composition.

  In one embodiment, the submicron particles may include a portion of a conductive material. In one aspect, 1-15 wt% of the conductive material may be submicron particles. In another aspect, 2-10 wt% of the conductive material may be submicron particles. In another aspect, 3-6 wt% of the conductive composition may be submicron particles.

  In one embodiment, a portion of the composition can have an average particle size d50 of 1.5 to 10 microns. In one aspect of this embodiment, 85 to 99 wt% of the inorganic components of the composition can have an average particle size d50 of 1.5 to 10 microns. In one aspect of this embodiment, a portion of the composition can have an average particle size d50 of 2.0 to 7.0 microns. In one aspect of this embodiment, a portion of the composition can have an average particle size d50 of 2.5 to 5.0 microns.

  In another aspect, the conductive material may include silver. In one aspect, 50-100 wt% of the conductive material may be silver. In another aspect, 70-99 wt%, 70-98 wt%, or 80-95 wt% of the conductive material may be silver.

Glass frit In one aspect of the invention, the composition comprises a glass frit composition. Glass frit compositions useful in the present invention are readily understood by those skilled in the art. For example, a glass frit composition useful for the composition used to make the front side solar cell electrode may be used. An exemplary glass frit composition includes lead borosilicate glass. In one embodiment, useful glass frit compositions of the present invention is SiO ₂ of 20~24wt%, 0.2~0.8wt% of Al ₂ O _3, 40~60wt% of PbO, 5-8 wt-% of B ₂ O ₃ may be included. In one embodiment, the glass frit composition may also optionally include 3-7 wt% TiO ₂ . In one embodiment, the glass frit composition may also optionally include one or more fluorine-containing components, including but not limited to salts such as fluorine, fluorides, metal oxyfluoride compounds, and the like. Such fluorine-containing component, but not limited to _{PbF 2, BiF 3, AlF 3} , NaF, LiF, KF, CsF, ZrF 4, TiF 4, and / or ZnF ₂ and the like. In one embodiment, the glass frit composition may include PbF ₂ of 8-13 weight%.

  In another aspect of this embodiment, the thick film composition may include electrically functional powder and glass ceramic frit dispersed in an organic medium. In one embodiment, these thick film conductor compositions can be used in semiconductor devices. In one aspect of this embodiment, the semiconductor device may be a solar cell or a photodiode.

Conductive Material In one embodiment, the thick film composition may include a functional phase that imparts appropriate electrical functional properties to the composition. In one embodiment, the electrically functional powder may be a conductive powder. In one embodiment, the electrical functional phase may include a conductive material (also referred to herein as conductive particles). The conductive particles may include, for example, conductive powder, conductive flakes, or a mixture thereof.

  In one embodiment, the conductive particles may include Ag. In another embodiment, the conductive particles may include silver (Ag) and aluminum (Al). In another embodiment, the conductive particles may include one or more of, for example, Cu, Au, Ag, Pd, Pt, Al, Ag—Pd, Pt—Au, and the like. In one embodiment, the conductive particles comprise (1) Al, Cu, Au, Ag, Pd, Pt, (2) an alloy of Al, Cu, Au, Ag, Pd, Pt, (3) 1 of these mixtures. One or more may be included.

  In one embodiment, the functional phase of the composition may include coated or uncoated silver particles that are electrically conductive. In embodiments where silver particles are coated, the silver particles are at least partially covered with a surfactant. In one embodiment, the surfactant may comprise one or more of the following non-limiting surfactants: stearic acid, palmitic acid, stearic acid salt, palmitic acid salt, lauric acid, palmitic acid, oleic acid , Salts of stearic acid, capric acid, myristic acid and linoleic acid, and mixtures thereof. The counter ion can be, but is not limited to, hydrogen, ammonium, sodium, potassium, and mixtures thereof.

  In one embodiment, the silver may be 60-90 wt% of the paste composition. In another embodiment, the silver may be 70-85 wt% of the paste composition. In another embodiment, the silver may be 75-85 wt% of the paste composition. In another embodiment, the silver may be 78-82 wt% of the paste composition.

  In one embodiment, the silver may be 90-99 wt% of the solids in the composition (i.e. excluding the organic vehicle). In another embodiment, the silver may be 92-97 wt% of the solids in the composition. In another embodiment, the silver may be 93-95 wt% of the solids in the composition.

  As used herein, “particle size” shall mean “average particle size” and “average particle size” means 50% volume distribution particle size. The volume distribution particle size may be determined by a number of methods understood by those skilled in the art including, but not limited to, laser diffraction and dispersion methods using a Microtrac particle size analyzer.

  In one embodiment, the portion of the conductive material may be submicron particles. In one aspect of this embodiment, the submicron particles can have an average particle size d50 of 0.1 to 1 micron. In another aspect, the submicron particles can have an average particle size d50 of 0.1 to 0.8 microns. In another aspect, the submicron particles can have an average particle size d50 of 0.2 to 0.6 microns.

  In one embodiment, 1-15 wt% of the conductive material may be submicron particles. In another aspect, 2-10 wt% of the conductive material may be submicron particles. In another aspect, 3-6 wt% of the conductive composition may be submicron particles.

  In one embodiment, a portion of the conductive material can have an average particle size d50 of 1.5 to 10 microns. In one aspect of this embodiment, 85-99 wt% of the conductive material can have an average particle size d50 of 1.5-10 microns. In one aspect of this embodiment, a portion of the conductive material can have an average particle size d50 of 2.0 to 7.0 microns. In one aspect of this embodiment, a portion of the conductive material can have an average particle size d50 of 2.5 to 5.0 microns.

Additives In one embodiment, the thick film composition may include one or more additives. In one embodiment, the additive may be selected from one or more of the following: (a) Zn, Pb, Bi, Gd, Ce, Zr, Ti, Mn, Sn, Ru, Co, Fe, Cu, Cr (B) a metal oxide of one or more metals selected from Zn, Pb, Bi, Gd, Ce, Zr, Ti, Mn, Sn, Ru, Co, Fe, Cu, Cr (C) any compound capable of producing the metal oxide of (b) upon firing, (d) a mixture thereof.

  In one embodiment, the additive may include a Zn-containing additive. Zn-containing additive is: (a) Zn, (b) Zn metal oxide, (c) any compound capable of producing Zn metal oxide upon firing, (d) one or more of the mixtures May be included. In one embodiment, the Zn-containing additive may comprise a Zn resinate.

  In one embodiment, the Zn-containing additive may include ZnO. In one embodiment, the portion of ZnO may include submicron particles.

  In one embodiment, ZnO may be present in the composition in the range of 2-10 wt% of the total composition. In one embodiment, ZnO may be present in the composition in the range of 3-7 wt% of the total composition. In one embodiment, ZnO may be present in the composition in the range of 4-6 wt% of the total composition.

Organic Medium In one embodiment, the thick film compositions described herein may include an organic medium. The inorganic component may be mixed with the organic medium, for example by mechanical mixing to form a paste. Various inert viscous materials can be used as the organic medium. In one embodiment, the organic medium may be one in which inorganic components are dispersed with appropriate stability. In one embodiment, the rheological properties of the media are, for the composition, stable solid dispersion, suitable viscosity and thixotropy for screen printing, adequate wettability of substrates and paste solids, good drying speed, and good. Some applicability including various firing characteristics can be lent. In one embodiment, the organic vehicle used in the thick film composition may be a non-aqueous inert liquid. The use of various organic vehicles that may or may not include thickeners, stabilizers, and / or other common additives is contemplated. The organic medium may be a polymer solvent solution. In one embodiment, the organic medium may also include one or more components such as a surfactant. In one embodiment, the polymer may be ethyl cellulose. Other exemplary polymers include ethyl hydroxyethyl cellulose, wood rosin, a mixture of ethyl cellulose and phenolic resin, lower alcohol polymethacrylate, ethylene glycol monoacetate monobutyl ether, or mixtures thereof. In one embodiment, solvents useful for the thick film compositions described herein include ester alcohols, terpenes such as alpha or beta terpineol, or kerosene, dibutyl phthalate, butyl carbitol, butyl carbitol acetate. Examples thereof include mixtures with other solvents such as tart, hexylene glycol, high-boiling alcohols and alcohol esters. In another embodiment, the organic medium may include a volatile liquid to promote rapid curing after application to the substrate.

  In one embodiment, for example, the polymer may be present in an organic medium ranging from 8 wt% to 11 wt% of the total composition. The composition of the thick film silver may be adjusted to a predetermined screen printable viscosity with the organic medium.

Firing Thick Film Composition In one embodiment, the organic medium may be removed during drying and firing of the semiconductor device. In one aspect, the glass frit, Ag, and additive may be sintered during firing to form an electrode. The fired electrode may include components, compositions, etc. resulting from the firing and sintering processes.

  In one aspect of this embodiment, the semiconductor device may be a solar cell or a photodiode.

FIELD Embodiments described herein relate generally to a method for manufacturing a semiconductor device. In one embodiment, the semiconductor device can be used for a solar cell device. The semiconductor device can include a front side electrode (irradiation side) that may include the composition described herein prior to firing.

  In one embodiment, a method for manufacturing a semiconductor device includes (a) a step of providing a semiconductor substrate, (b) a step of applying an insulating film to the semiconductor substrate, and (c) applying the composition described herein to the insulating film. And (d) a step of firing the apparatus.

  Exemplary semiconductor substrates useful in the methods and apparatus described herein will be understood by those skilled in the art. Exemplary semiconductor substrates include, but are not limited to single crystal silicon, polycrystalline silicon, and ribbon silicon. The semiconductor substrate can have a bond. The semiconductor substrate may be doped with phosphorus and boron to form a p / n junction. Those skilled in the art understand how to dope semiconductor substrates.

  As will be appreciated by those skilled in the art, the semiconductor substrate may vary in size (length x width) and thickness. In non-limiting examples, the thickness of the semiconductor substrate can be 50-500 microns, 100-300 microns, or 140-200 microns. In non-limiting examples, the length and width of the semiconductor substrate may both be 100-250 mm, 125-200 mm, or 125-156 mm.

Exemplary insulating films useful in the methods and apparatus described herein will be understood by those skilled in the art. Exemplary insulating films include, but are not limited to, silicon nitride, silicon oxide, titanium oxide, SiN _x : H, hydrogenated amorphous silicon nitride, and silicon oxide / titanium oxide films. The insulating film may be formed by PECVD, CVD, and / or other techniques well known to those skilled in the art. In one embodiment where the insulating film is silicon nitride, the silicon nitride film may be formed by plasma enhanced chemical vapor deposition (PECVD), thermal CVD processing, or physical vapor deposition (PVD). In embodiments where the insulating film is silicon oxide, the silicon oxide film may be formed by thermal oxidation, thermal CVD, plasma CVD, or PVD. The insulating film (or layer) may be referred to as an anti-reflective coating (ARC).

  The compositions described herein can be applied to ARC coated semiconductor substrates by a variety of methods well known to those skilled in the art including, but not limited to, screen printing, inkjet, coextrusion, syringe dispensing, direct drawing, spray inkjet. It's okay. In one embodiment, the composition may be applied to a substrate using the methods and apparatus described in US Patent Publication No. 2003/0100824, which is incorporated herein by reference. The composition may be applied in a pattern. The composition may be applied in a predetermined shape and at a predetermined location. In one embodiment, the composition can be used to form both conductive fingers and bus bars of the front electrode. In one embodiment, the line width of the conductive fingers may be 10-200 microns, 40-150 microns, or 60-100 microns. In one embodiment, the line width of the conductive fingers may be 10-100 microns, 15-80 microns, or 20-75 microns. In one embodiment, the conductive finger line thickness may be 5-50 microns, 10-35 microns, or 15-30 microns. In another embodiment, the composition can be used to form conductive Si contact fingers.

  The composition coated on the ARC coated semiconductor substrate may be dried and then fired, for example, for 0.5-10 minutes, as will be appreciated by those skilled in the art. In one embodiment, volatile solvents and organics may be removed during the drying process. Firing conditions will be understood by those skilled in the art. Under exemplary and non-limiting firing conditions, the silicon wafer substrate is heated to a maximum temperature of 600-900 ° C. for 1 second to 2 minutes. In one embodiment, the maximum silicon wafer temperature reached during firing is in the range of 650-800 ° C. for 1-10 seconds. In another embodiment, the electrode formed from the conductive thick film composition may be fired in an atmosphere composed of a mixed gas of oxygen and nitrogen. This firing process removes the organic medium and sinters the glass frit with the Ag powder in the conductive thick film composition. In another embodiment, the electrode formed from the conductive thick film composition may be fired at a temperature above the organic media removal temperature in an oxygen free inert atmosphere. This firing process sinters or melts a base metal conductive material such as copper in the thick film composition.

  In one embodiment, during firing, the fired electrode (preferably a finger) reacts with the insulating film to penetrate the insulating film and form an electrical contact with the silicon substrate.

  In another embodiment, prior to firing, other conductive and device reinforcing materials are applied to the opposite areas of the semiconductor device and co-fired or continuously fired with the compositions described herein. The opposite area of the device is on the opposite side of the device. The material functions as an electrical contact, a passivation layer, and a solderable tab region.

  In one embodiment, the opposite area may be on the non-irradiated (back) side of the device. In one aspect of this embodiment, the backside conductive material may include aluminum. Exemplary backside aluminum-containing compositions and coating methods are described, for example, in US 2006/0272700, which is incorporated herein by reference.

  In another aspect, the solderable tab material may include aluminum and silver. Exemplary tab compositions comprising aluminum and silver are described, for example, in US Patent Application Publication No. 2006/0231803, which is incorporated herein by reference.

  In another embodiment, the material applied to the opposite region of the device is adjacent to the materials described herein because of the p and n regions formed side by side. Such devices place all metal contact material on the non-irradiated (back) side of the device to maximize the incident light on the irradiated (front) side.

  The semiconductor device may be manufactured by the following method from a structural member including a semiconductor substrate having a junction and a silicon nitride insulating film formed on the main surface thereof. A manufacturing method of a semiconductor device includes a step of applying a conductive thick film composition having an ability to penetrate an insulating film in a predetermined shape and at a predetermined position (such as coating and printing) on the insulating film, And firing the thick film composition to melt and penetrate the insulating film, thereby providing an electrical contact with the silicon substrate. The conductive thick film composition comprises a silver powder dispersed in an organic vehicle as described herein, a Zn-containing additive, a glass or glass powder mixture having a softening temperature of 300-600 ° C, Optionally, a thick film paste composition comprising an additional metal / metal oxide additive.

  One embodiment of the invention relates to a semiconductor device manufactured by the method described herein. Devices comprising the compositions described herein may comprise zinc silicate as described above.

  One embodiment of the present invention relates to a semiconductor device manufactured by the above method.

  Additional substrates, devices, manufacturing methods, etc. that can be used with the thick film compositions described herein are disclosed in US Patent Application Publication No. 2006/0231801, US Patent Application, which is hereby incorporated by reference in its entirety. This is described in Japanese Patent Application Publication No. 2006/0231804 and US Patent Application Publication No. 2006/0231800.

  The organic medium was prepared by dissolving the polymer in an organic solvent at about 100 ° C. In the organic medium, other ingredients including silver powder, glass frit, zinc oxide and other additives were added. The resulting mixture was dispersed by a three roll kneading process well known in the thick film paste manufacturing industry. Compositions I, II and III shown in Table 1 were formed.

  Composition I and II pastes were filtered through Roki 40L-SHP-200XS filter capsules prior to printing. Composition III was used without filtration.

  The paste was evaluated at room temperature with a 3D-450 Smart Pump ™ printer from nScript Inc using a reusable ceramic pen tip with ID / OD 50/75 μm. The pump pressure was 10 psi to 100 psi. The printing speed was 200 mm / second to 300 mm / second. The gap between the pen tip and the substrate surface is 150 μm.

  Groups of 10 4 inch long lines were printed, dried in a box oven at 150 ° C. for 20 minutes, and then fired in a belt furnace at 850 ° C. peak temperature for 2 minutes.

Example I
Composition I was able to pass through a 50/75 micron pen tip under a pump pressure of less than 50 psi for less than 5 minutes before the pen tip was plugged. The best results fired lines were 83 microns wide and 13 microns high.

Example II
Composition I was able to pass the 75/125 micron pen tip under a pump pressure of less than 60 psi for less than 30 minutes before the pen tip was plugged. The best results fired lines were 100 microns wide and 12 microns high.

Example III
Composition II was able to pass through a 50/75 micron pen tip under pump pressure in the range of 10 psi to 100 psi for at least 30 minutes before printing was stopped. The best results fired lines were 89 microns wide and 19 microns high.

Example IV
Mixture of Composition II and Composition III in a 95.5 to 4.5 weight percentage ratio passes through a 50/75 micron pen tip under pump pressure in the range of 10 psi to 80 psi for at least 3 hours before printing is stopped. We were able to. The best results fired lines were 67 microns wide and 25 microns high.

Example V
Composition III could not be printed through a 50/75 micron pen tip under a pump pressure greater than 30 psi. Under 30 psi, printing continued for less than 5 seconds before the pen tip was blocked.

Example VI
Composition III could be printed through a 75/125 micron pen tip under a pump pressure greater than 60 psi. Under 60 psi, printing continued for less than 5 minutes before the pen tip was blocked.

Example VII
A series of blends of Compositions II and III with weight ratios ranging from 90:10 to 10:90 were prepared and printed. When the weight ratio of Composition III was greater than 30%, the 50/75 micron pen tip was plugged within 1 minute.

Example VIII
Analyze the efficiency of the printed substrate. An exemplary efficiency test is shown below. It is expected that the efficiency of the solar cell of Example IV will be greater than the efficiency of the solar cells of other examples.

Test Procedure-Efficiency Solar cells made according to the methods described herein are tested for conversion efficiency. An exemplary method for testing efficiency is shown below.

  In one embodiment, solar cells made according to the methods described herein are placed in a commercially available IV test apparatus (ST-1000) for measuring efficiency. The Xe arc lamp in the IV test apparatus simulated the direct sunlight with a well-known intensity and irradiated the front surface of the battery.

  The test apparatus uses a multipoint direct contact method to measure current (I) and voltage (V) with a load resistance setting of about 400 to establish the battery's IV characteristic curve. Both filling factor (FF) and efficiency (Eff) are calculated from the IV characteristic curve.

Claims (15)

(A) preparing a semiconductor substrate, one or more insulating films, a thick film composition;
(B) applying the insulating film to the semiconductor substrate;
(C) applying the thick film composition to an insulating film on the semiconductor substrate;
(D) firing the semiconductor, insulating film, and thick film composition;
A thick film composition comprising: a semiconductor device manufactured by a method comprising:
(I) one or more conductive materials,
(Ii) one or more inorganic binders,
(Iii) an organic vehicle,
Wherein 1-15% of the inorganic components are submicron particles. A semiconductor device including an electrode, wherein the electrode is
(A) one or more conductive materials,
(B) one or more inorganic binders,
(C) an organic vehicle,
A device comprising 1 to 15% of the inorganic component is submicron particles.   The apparatus of claim 2 wherein 85-99% of the inorganic components have a d50 of 1.5-10 microns.   The apparatus of claim 2, wherein the one or more conductive materials comprises silver.   The apparatus of claim 4, wherein the submicron particles comprise silver.   The apparatus of claim 2, wherein the submicron particles have a d50 of 0.1 to 1 micron.   The apparatus of claim 2, wherein the submicron particles have a d50 of 0.1 to 0.6 microns.   The apparatus of claim 2, wherein the inorganic component has a bimodal particle size distribution.   The apparatus of claim 2, wherein the thick film composition further comprises one or more additives. The one or more additives are:
(A) a metal selected from Zn, Pb, Bi, Gd, Ce, Zr, Ti, Mn, Sn, Ru, Co, Fe, Cu, Cr;
(B) a metal oxide of one or more metals selected from Zn, Pb, Bi, Gd, Ce, Zr, Ti, Mn, Sn, Ru, Co, Fe, Cu, Cr;
(C) any compound capable of producing the metal oxide of (b) upon firing;
(D) a mixture thereof;
The apparatus of claim 9, comprising a component selected from the group consisting of:   The apparatus of claim 10, wherein the one or more inorganic additives comprise ZnO.   The apparatus of claim 5, wherein the submicron particles further comprise ZnO and an inorganic binder.   The apparatus according to claim 2, further comprising an insulating film and a semiconductor substrate.   A solar cell comprising the semiconductor device according to claim 2.   14. The device of claim 13, wherein the insulating film includes one or more components selected from titanium oxide, silicon nitride, SiNx: H, silicon oxide, silicon oxide / titanium oxide.

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