US5850064A
Expired / Lapsed
US
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Method for photolytic liquid phase synthesis of silicon and germanium nanocrystalline materials
Assignee: Starfire Electronic Development and Marketing Ltd
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Filing: 1997-04-11
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Granted: 1998-12-15
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Expires: 2017-04-11
Abstract
Abstract A method is described for the liquid phase synthesis of particles. The particles are composed of silicon or germanium and are optionally produced at sizes such that the particles exhibit quantum size effects. The particles are produced from an organometallic (tetra-organosilicon or tetra-organogermanium) precursors which is dissolved in a solvent that transmits a wavelength of light that photolyzes the precursor. The reaction is carried out under an inert atmosphere. A passivating agent is added to arrest particle growth and impart solubility to the particle. Optionally, a dopant is incorporated into the particle in the course of production so as to modify the electronic properties of the semiconductor particle.
Inventors
- 👤 Avery Nathan Goldstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:15
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/16; B22F9/30; B82; B82Y; B82Y30/00; C; C01; C01B; C01B33/00; C01B33/02; C01B33/021; C22; C22B; C22B41/00; B22F2999/00; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24893; Y10T428/24909; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
186 words
A method for producing silicon or germanium particles, said method comprising: sealing an organometallic precursor of the formula, (M 1 )RR'R"R'", wherein R, R', R", and R'" are each independently selected from the group consisting of hydrogen, alkyls containing less than 13 carbon atoms, monounsaturated alkenyls containing less than 9 carbon atoms, alkynyls containing less than 9 carbon atoms and aromatics containing less than 20 carbon atoms, and M 1 is selected from the group consisting of silicon and germanium under an inert atmosphere within a reaction vessel transmissive to a photolysis wavelength; adding a liquid solvent transmissive to said photolysis wavelength to said reaction vessel, said solvent having a molecular structure, the structure being free of oxygen; and exposing said reaction vessel to a light source, wherein said light source produces sufficient flux of said photolysis wavelength to photolyze said precursor within said reaction vessel to form a M 1 --M 1 bond; and maintaining a kinetically stable population of M 1 -comprising radicals with the light source flux, said population reacting with said M 3 --M 1 bond to form one of said particles.
Claim 2
Independent Claim
186 words
A method for producing silicon or germanium particles, said method comprising: sealing an organometallic precursor of the formula, (M 1 )RR'R"R'", wherein R, R', R", and R'" are each independently selected from the group consisting of hydrogen, alkyls containing less than 13 carbon atoms, monounsaturated alkenyls containing less than 9 carbon atoms, alkynyls containing less than 9 carbon atoms and aromatics containing less than 20 carbon atoms, and M 1 is selected from the group consisting of silicon and germanium under an inert atmosphere within a reaction vessel transmissive to a photolysis wavelength; adding a liquid solvent transmissive to said photolysis wavelength to said reaction vessel, said solvent having a molecular structure, the structure being free of oxygen; and exposing said reaction vessel to a light source, wherein said light source produces sufficient flux of said photolysis wavelength to photolyze said precursor within said reaction vessel to form a M 1 --M 1 bond; and maintaining a kinetically stable population of M 1 -comprising radicals with the light source flux, said population reacting with said M 3 --M 1 bond to form one of said particles.
Claim 3
Dependent Claim
23 words
The method of claim 1 further comprising the step of adding a passivating agent to arrest changes in particle diameter of said particles.
Claim 4
Dependent Claim
88 words
The method of claim 2 wherein the passivating agent is selected from the group consisting of: perfluoroalkene-, perfluoroalkene-sulfonic acid-, alkylene-methacrylic acid-, polyesters-polymers; nonionic surfactants; organometallic species of the formula R 4-n (M 2 )X n , wherein n is 1, 2 or 3; R is an aliphatic group containing less than 9 carbon atoms, X is hydrogen or fluorine, and M 2 is silicon or germanium; and small organic molecules of molecular weight less than about 500 and containing a nonfacile heteroatom of oxygen, nitrogen, sulfur, or phosphorus.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein said photolysis wavelength is between about 180 nanometers and 250 nanometers.
Claim 6
Dependent Claim
17 words
The method of claim 1 wherein said photolysis wavelength is between about 750 nanometers and 1200 nanometers.
Claim 7
Dependent Claim
22 words
The method of claim 1 wherein said organometallic precursor is symmetric, such that R, R', R", and R'" are all compositionally identical.
Claim 8
Dependent Claim
15 words
The method of claim 1 wherein said organometallic precursor yields volatile organic fragments upon photolysis.
Claim 9
Dependent Claim
33 words
The method of claim 1 further comprising the step of: adding a dopant percursor having a dopant atom therein to said reaction vessel such that the dopant atom is incorporated into said particles.
Claim 10
Dependent Claim
13 words
The method of claim 8 wherein said dopant precursor is an organometallic percursor.
Claim 11
Dependent Claim
17 words
The method of claim 1 wherein said inert atmosphere has a pressure of one atmosphere or less.
Claim 12
Dependent Claim
12 words
The method of claim 1 wherein said particles exhibit quantum confinement effects.
Claim 13
Independent Claim
146 words
A method for producing silicon or germanium particles, said method comprising: sealing an organometallic precursor of the formula, (M 2 )RR'R"R'", wherein R, R', R", and R'"are each independently selected from the group consisting of hydrogen, alkyls containing less than 13 carbon atoms, monounsaturated alkenyls containing less than 9 carbon atoms, alkynyls containing less than 9 carbon atoms and aromatics containing less than 20 carbon atoms, and M 1 is selected from the group consisting of silicon and germanium under an inert atmosphere within a reaction vessel transmissive to a photolysis wavelength; adding a liquid solvent transmissive to said photolysis wavelength to said reaction vessel; exposing said reaction vessel to a light source that produces said photolysis wavelength to yield said particles; and adding a dopant precursor having a dopant atom therein to said reaction vessel such that the dopant atom is incorporated into said particles.
Claim 14
Independent Claim
146 words
A method for producing silicon or germanium particles, said method comprising: sealing an organometallic precursor of the formula, (M 2 )RR'R"R'", wherein R, R', R", and R'"are each independently selected from the group consisting of hydrogen, alkyls containing less than 13 carbon atoms, monounsaturated alkenyls containing less than 9 carbon atoms, alkynyls containing less than 9 carbon atoms and aromatics containing less than 20 carbon atoms, and M 1 is selected from the group consisting of silicon and germanium under an inert atmosphere within a reaction vessel transmissive to a photolysis wavelength; adding a liquid solvent transmissive to said photolysis wavelength to said reaction vessel; exposing said reaction vessel to a light source that produces said photolysis wavelength to yield said particles; and adding a dopant precursor having a dopant atom therein to said reaction vessel such that the dopant atom is incorporated into said particles.
Claim 15
Dependent Claim
38 words
The method of claim 12 wherein the dopant atom is selected from the group consisting of: lithium, beryllium, boron, nitrogen, sodium, magnesium, aluminum, phosphorus, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, arsenic, indium and antimony.
Claim 16
Dependent Claim
12 words
The method of claim 12 wherein said particles exhibit quantum confinement effects.
Claim 17
Dependent Claim
20 words
The method of claim 12 further comprising: adding a passivating agent to arrest changes in particle diameter of said particles.
Claim 18
Independent Claim
141 words
A method for producing silicon or germanium particles, said method comprising: sealing an organometallic precursor of the formula, (M 1 )RR'R"R'", wherein R, R', R", and R'" are each independently selected from the group consisting of hydrogen, alkyls containing less than 13 carbon atoms, monounsaturated alkenyls containing less than 9 carbon atoms, alkynyls containing less than 9 carbon atoms and aromatics containing less than 20 carbon atoms, and M 1 is selected from the group consisting of silicon and germanium under an inert atmosphere of about one atmosphere or less, within a reaction vessel capable of transmitting a photolysis wavelength; adding a liquid solvent capable of transmitting said photolysis wavelength to said reaction vessel; exposing said reaction vessel to a light source that produces said photolysis wavelength; and adding a passivating agent to arrest changes in particle diameter of said particles.
Claim 19
Independent Claim
141 words
A method for producing silicon or germanium particles, said method comprising: sealing an organometallic precursor of the formula, (M 1 )RR'R"R'", wherein R, R', R", and R'" are each independently selected from the group consisting of hydrogen, alkyls containing less than 13 carbon atoms, monounsaturated alkenyls containing less than 9 carbon atoms, alkynyls containing less than 9 carbon atoms and aromatics containing less than 20 carbon atoms, and M 1 is selected from the group consisting of silicon and germanium under an inert atmosphere of about one atmosphere or less, within a reaction vessel capable of transmitting a photolysis wavelength; adding a liquid solvent capable of transmitting said photolysis wavelength to said reaction vessel; exposing said reaction vessel to a light source that produces said photolysis wavelength; and adding a passivating agent to arrest changes in particle diameter of said particles.
Claim 20
Dependent Claim
12 words
The method of claim 16 wherein said particles exhibit quantum confinement effects.
Claim 21
Dependent Claim
17 words
The method of claim 16 wherein said photolysis wavelength is between about 180 nanometers and 250 nanometers.
Claim 22
Dependent Claim
15 words
The method of claim 16 wherein said organometallic precursor yields volatile organic fragments upon photolysis.
Claim 23
Dependent Claim
87 words
The method of claim 16 wherein the passivating agent is selected from the group consisting of: perfluoroalkene-, perfluoroalkene-sulfonic acid-, alkylene-methacrylic acid-, polyesters-polymers; nonionic surfactants; organometallics species of the formula R 4-n (M 2 )X n , wherein n is 1, 2 or 3; R is an aliphatic group containing less than 9 carbon atoms, X is hydrogen or fluorine, and M 2 is silicon or germanium; and small organic molecules of molecular weight less than about 500 and containing a nonfacile heteroatom of oxygen, nitrogen, sulfur,or phosphorus.
References Cited (Backward Citations)
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