Porous silicon organic vapor sensor

In this paper, a porous silicon (PS) layer was investigated as a sensing material to detect organic vapors. The PS was obtained by electrochemical anodization of p-type crystalline silicon (c-Si) in an ethanoic HF solution in order to produce a mesoporous material. The change in the electrical resistance value of the PS layer was used as parameter to sense the presence of the organic vapors (methanol, ethanol, isopropanol, xilene, acetone or water in this work). Gravimetry and infrared spectroscopy (FTIR) were used to characterize the PS layers. As a result, we obtain that the thickness and sensing area of the PS layer produce a great difference in the sensor response. It was also observed that the sensor device had best response for methanol or acetone vapors.