In this study, femtosecond (FS) laser irradiation with different laser energy densities of 138, 276, and 414 mJ/cm
2 is applied to SnO
2-nanowire (NW) gas sensors, and the effect of the FS laser irradiation on the gas sensor response toward toluene
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In this study, femtosecond (FS) laser irradiation with different laser energy densities of 138, 276, and 414 mJ/cm
2 is applied to SnO
2-nanowire (NW) gas sensors, and the effect of the FS laser irradiation on the gas sensor response toward toluene (C
7H
8) gas is investigated. The FS laser irradiation causes oxygen deficiency in the SnO
2 NWs and forms SnO and SnO
x. Moreover, an embossing surface with multiple nano-sized bumps is created on the SnO
2 NW surface because of the FS laser irradiation. The FS laser-irradiated SnO
2-NW gas sensor exhibits superior sensing performance compared with the pristine SnO
2-NW gas sensor. Moreover, the FS laser energy density significantly affects gas-sensing performance, and the highest sensor response is achieved by the gas sensor irradiated at 138 mJ/cm
2. The long-term stability test of the laser-irradiated SnO
2-NW gas sensor is performed by comparing fresh and 6-month-old gas sensors in different gas concentrations and relative humidity levels. Comparable gas-sensing behaviors are examined between the fresh and 6-month-old gas sensor, and this verifies the robustness of the laser-irradiated SnO
2-NW gas sensor.
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