Plasmonic transparent conducting metal oxide nanoparticles and films for optical sensing applications
First Claim
1. A method of a detecting a change in a chemical composition of a gas stream comprising:
- placing a doped oxide material in the gas stream, where the gas stream has a temperature of at least 100°
C., and where the doped oxide material comprises a doped metal oxide, where the doped metal oxide has a carrier concentration of at least 1018/cm3, a bandgap of at least 2 eV, and an electronic conductivity of at least 101 S/cm at a temperature of 25°
C.;
contacting the doped metal oxide with a monitored stream, where the monitored stream is at least a portion of the gas stream, and where the monitored stream has a temperature of at least 100°
C.;
illuminating the doped metal oxide with a light source emitting incident light;
collecting exiting light, where the exiting light is light that originates at the light source and is transmitted, reflected, scattered or a combination thereof by the doped metal oxide;
monitoring an optical signal based on a comparison of the incident light and the exiting light using optical spectroscopy; and
detecting a shift in the optical signal, thereby detecting the change in the chemical composition, and thereby monitoring the chemical composition of the gas stream.
1 Assignment
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Accused Products
Abstract
The disclosure relates to a method of detecting a change in a chemical composition by contacting a doped oxide material with a monitored stream, illuminating the doped oxide material with incident light, collecting exiting light, monitoring an optical signal based on a comparison of the incident light and the exiting light, and detecting a shift in the optical signal. The doped metal oxide has a carrier concentration of at least 1018/cm3, a bandgap of at least 2 eV, and an electronic conductivity of at least 101 S/cm, where parameters are specified at a temperature of 25° C. The optical response of the doped oxide materials results from the high carrier concentration of the doped metal oxide, and the resulting impact of changing gas atmospheres on that relatively high carrier concentration. These changes in effective carrier densities of conducting metal oxide nanoparticles are postulated to be responsible for the change in measured optical absorption associated with free carriers. Exemplary doped metal oxides include but are not limited to Al-doped ZnO, Sn-doped In2O3, Nb-doped TiO2, and F-doped SnO2.
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Citations
20 Claims
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1. A method of a detecting a change in a chemical composition of a gas stream comprising:
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placing a doped oxide material in the gas stream, where the gas stream has a temperature of at least 100°
C., and where the doped oxide material comprises a doped metal oxide, where the doped metal oxide has a carrier concentration of at least 1018/cm3, a bandgap of at least 2 eV, and an electronic conductivity of at least 101 S/cm at a temperature of 25°
C.;contacting the doped metal oxide with a monitored stream, where the monitored stream is at least a portion of the gas stream, and where the monitored stream has a temperature of at least 100°
C.;illuminating the doped metal oxide with a light source emitting incident light; collecting exiting light, where the exiting light is light that originates at the light source and is transmitted, reflected, scattered or a combination thereof by the doped metal oxide; monitoring an optical signal based on a comparison of the incident light and the exiting light using optical spectroscopy; and detecting a shift in the optical signal, thereby detecting the change in the chemical composition, and thereby monitoring the chemical composition of the gas stream. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of a detecting a change in a concentration of a reducing gas in a gas stream comprising:
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generating the gas stream, where the gas stream comprises the reducing gas, and where the gas stream has a temperature of at least 200°
C.;placing a doped oxide material in a gas stream, where the doped oxide material comprises a doped metal oxide, where the doped metal oxide has an empirical formula MaOb where M comprises one or more elements and where O comprises an oxygen anion, and here the doped metal oxide has a carrier concentration of at least 1019/cm3, a bandgap of at least 2 eV, and an electronic conductivity of at least 102 S/cm at a temperature of 25°
C.;contacting the doped metal oxide with a monitored stream, where the monitored stream is at least a portion of the gas stream, and where the monitored stream comprises the reducing gas, and where the monitored stream has a temperature of at least 200°
C.;illuminating doped metal oxide with a light source emitting incident light; collecting exiting light, where the exiting light is light that originates at the light source and is transmitted, reflected, or a combination thereof by the doped metal oxide; monitoring an optical signal based on a comparison of the incident light and the exiting light using optical spectroscopy; and detecting a shift in the optical signal, thereby detecting the change in the concentration of the reducing gas in the gas stream. - View Dependent Claims (18, 19, 20)
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Specification