Temperature dependence of thermally‐carbonized porous silicon humidity sensor

Abstract

Thermal carbonization of porous silicon (PS) at 820 °C under acetylene atmosphere is an appropriate method for humidity sensing purposes. It produces stable and hydrophilic surface still maintaining originally large specific surface area of PS. We report the temperature dependence of various electrical parameters measured for the thermally-carbonized PS humidity sensor. Capacitance of the sensor in dry air (6 RH%) is almost constant at various temperatures, whereas in higher relative humidity values, the temperature dependence becomes evident. The resistance variation of the sensor is less dependent on RH as the temperature increases. While the capacitance showed linear behavior as a function of temperature, the resistance had a clear non-linear temperature dependence. In order to get information about the effects of frequency on capacitance values, we measured a phase angle and admittance of the sensor as a function of frequency at three different temperatures in low and high humidity. According to these results, it is preferable to operate this sensor construction using low frequency (<1 kHz).

Ultrafast humidity sensor based on liquid phase exfoliated graphene

“…To demonstrate operational performance of our sensors under different conditions, we present sensor response at different temperatures (figure S9) and in a flexed state (figure S10). Sensitivity decreases with temperature, as is common for chemiresistive humidity sensors [30].…”

Synthesis of Guanine/Vermiculite Two-Dimensional Nanocomposites for Wireless Humidity Sensing in Nut Storage Environment

“…Excellent humidity sensors require a large surface area that is sensitive to water molecules, allowing the molecules to adsorb . Therefore, various novel materials with large specific surface areas, including carbon nanotubes, nanodiamonds, porous silicon, and metal oxides, , have been investigated for use in humidity sensors.…”

The Effect of N2 in Vapor Detectors Based on Porous Silicon Layers

“…Several attempts to build devices approaching the commercial requirements in stability, reproducibility and cost-benefit variables have been reported by various groups (7). Some applications have been developed as humidity sensors (8)(9)(10). The sensing principle is the fact that the water molecules infiltrate the porous media and change the surface reactivity of the pores.…”