CO sensitivity of undoped-ZnO, Cr-ZnO and Cu-ZnO thin films obtained by spray pyrolysis
In this work, we present the gas-sensing properties of chemically sprayed undoped (ZnO), copper-doped (Cu-ZnO), and chromium-doped ZnO thin films (Cr-ZnO), in an atmosphere of carbon monoxide, CO. Films were deposited at 400°C, using zinc acetylacetonate as zinc precursor. Three different atomic concentration ratios of the dopant were tested. A maximum sensitivity of the order of four orders of magnitude was obtained at measurement temperatures of 200 and 300°C in an atmosphere containing 100 ppm of CO. It was found that chromium doping favors a higher sensitivity at lower measurement temperatures (200°C), whereas the best sensitivity appears in copper-doped ZnO films at higher measurement temperatures (300° C). The thinnest films exhibited higher sensitivities.
| Main Authors: | , , , , |
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| Format: | Digital revista |
| Language: | English |
| Published: |
Sociedad Mexicana de Física
2006
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| Online Access: | http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0035-001X2006000800003 |
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| Summary: | In this work, we present the gas-sensing properties of chemically sprayed undoped (ZnO), copper-doped (Cu-ZnO), and chromium-doped ZnO thin films (Cr-ZnO), in an atmosphere of carbon monoxide, CO. Films were deposited at 400°C, using zinc acetylacetonate as zinc precursor. Three different atomic concentration ratios of the dopant were tested. A maximum sensitivity of the order of four orders of magnitude was obtained at measurement temperatures of 200 and 300°C in an atmosphere containing 100 ppm of CO. It was found that chromium doping favors a higher sensitivity at lower measurement temperatures (200°C), whereas the best sensitivity appears in copper-doped ZnO films at higher measurement temperatures (300° C). The thinnest films exhibited higher sensitivities. |
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