Electrical Properties of Porous Silicon for N2 Gas Sensor

Abstract

The application of porous silicon (PSi) for gas sensing devices has gained a considerable attention in the last decade. This work considers the electrical features of PSi layers prepared by electrochemical etching. We find that in order to get a better understanding of the absorption properties of PSi surface, it is necessary to know how the PSi morphology depends on the etching parameters. The physical structure of PSi, i.e., porosity, and pore size distribution can be controlled by changing the Hydrofluoric Acid concentration, current density, anodizing length and etching time in anodizing procedure. We describe our test system for gas sensors and investigate on the electrical behavior of PSi layers (p-type) in N 2 gas for various fabrication conditions. The results show that the current density increases significantly as N 2 gas is adsorbed. The measurements of the I-V characteristics were carried out at atmospheric pressure, room temperature, and with N 2 gas as well.

Study of the Vacuum Pressure Sensing from the Electrical Resistance Response of Porous Silicon Fabricated via Photo-Electrochemical Technique

“…Figure 6 shows the gradual decrease in electrical resistance of PSi samples inside the vacuum chamber with different etching times at room temperature. We note that the value of the electrical resistance of porous silicon after the vacuum procedure decreases compared to the electrical resistance that increases in the presence of gas molecules, as shown in previous studies [4,8,19,20,28]. This is due to the fact that any physical phenomenon changes happened according to the change of vacuum, which depends on any vacuum gauge, and this change in the phenomenon must be linearly proportional to the change of vacuum as it is an indirect gauge.…”

“…The electrical or optical properties such as conductivity, capacitance, and refractive index may change more depending on the adsorption of molecules on the surface. The microstructure and the surface's physical properties determine the adsorption mechanism of gas molecules on the PSi surface [8]. Because of the improvement in Responsiveness, porous silicon can be used instead of silicone in gas sensor applications.…”

A high sensitivity double-roughness-structure based on the porous silicon with graphene embedded for the sensing improvement on the non-reactive molecules

“…With the high STVR of the PS-layers, many researchers try to fill various specific materials into the nano-pores of PS-layers [3] to improve the reactivity of sensors. It makes the PS-based composite structure a new selection for the sensor applications [4] in the Si-based VLSI technology. Our team has successively put forward some novel manufacturing approaches of PS-layers.…”

Design & Development of Laser Etched Porous-Silicon Capacitive Chip for Rapid Sensing of Pesticide Solvents

“…The main advantage of the PSS characteristics changed due to the material inside the pore [2][3]. This makes the PSS more suitable for optical, electrical and thermal sensing application like batteries, drug-delivery system, humidity sensor, solar cell, toxic gas detection, Herbicides and pesticides detection in agriculture, pressure sensor, glucose detection, pathology, and thermal sensing application [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. The optical sensing easily works in hazardous environment, gives fastest output, whereas sensing equipment are costly as well as there is environment interference.…”