Toluene sensing characteristics of tin oxide-based gas sensor deposited with various amounts of metalloporphyrin

Abstract

In this study, the sensing characteristics of tin oxide-based gas sensors deposit with different amounts of metalloporphyrin, which is a functionalization substance, are evaluated. The mass of metalloporphyrin deposited is 3, 10, 20, 30, and 40 mg for 5 different sensors prepared. The deposition of 3 mg of metalloporphyrin result in an island form of functionalization instead of a thin film; meanwhile, thin films with thicknesses of 25, 35, 74, and 92 nm are formed for the other four cases. As the deposition amount of metalloporphyrin increase, the performance of the sensor deteriorate. The samples are prepared by subdividing the amount of metalloporphyrin source to determine the optimized deposition amount. A sample is prepared with deposition amounts ranging between 1 to 10 mg. The sensors deposit with 3–5 mg metalloporphyrin has excellent response, response, and recovery time characteristics.

Incompatibility of Pure SnO2 Thin Films for Room-Temperature Gas Sensing Application

“…The schematic diagram of the sensing setup is shown in Figure . The sensor response was calculated as S = R normala R normalg where R a and R g are the resistance in the absence and presence of target gas, respectively . Response time is the time taken by the sensor to reach 90% of its final value in the presence of target gas.…”

“…The sensor response was calculated 22 as where R a and R g are the resistance in the absence and presence of target gas, respectively. 23 Response time is the time taken by the sensor to reach 90% of its final value in the presence of target gas. Recovery time is the time taken by the sensor to reach 10% of the initial value on the removal of target gas.…”