Organic vapor detection using a color-difference image technique for distributed Bragg reflector structured porous silicon

Porous silicon gas sensors

“…The detection of toxins, volatile organic compounds, polycyclic aromatic hydrocarbons, and explosives on the level of at least a few ppb was demonstrated using stacked PSi photonic crystals, multilayer structures, and distributed Bragg refl ector structured PSi (Ruminski et al ., 2008;Park et al ., 2010;Kelly et al ., 2011;Kim et al ., 2011). PSi layers with embedded metal oxides, as well as PSi-polymer hybrid structures, have recently been proposed for gas-sensing applications (Belhousse et al ., 2010;Bolotov et al ., 2011;Moshnikov et al ., 2012).…”

Electrostatic gas sensor with a porous silicon diaphragm

“…First, it is well known that the intensity of photoluminescence (PL) emitted from porous silicon by excitation light varies after exposure to organic vapors [12,13]. Moreover, the surface reflectivity of the porous silicon layer is changed by chemical gases [5,14]. This property is widely exploited because measurement of reflectivity change is easier than that of PL intensity change.…”

A distributed Bragg reflector porous silicon layer for optical interferometric sensing of organic vapor

“…One of the main problems is that the luminescence intensity is insufficient and a method to control its output wavelength has not yet been developed [6]. Recently, because of the interesting morphological and physical properties of the PS layer, the research focus has begun moving toward sensing application areas such as chemical [7][8][9][10] and biological sensors [11][12][13][14]. PS is an ideal material for sensors because of its sponge-like structure.…”

“…This large value accounts for the enhanced reactivity of PS with various adsorptive substances. Furthermore, the adsorption of chemical or biological substances into the pores modifies the electrical and optical properties of PS, such as the electrical conductivity [10,[18][19][20], reflectance [8,[19][20][21], and photoluminescence (PL) [10,18,19,22]. Moreover, PS is a low-cost material capable of being operated at room temperature and completely compatible with very-largescale-integration (VLSI) processes.…”

“…Moreover, PS is a low-cost material capable of being operated at room temperature and completely compatible with very-largescale-integration (VLSI) processes. These properties of PS have led to its use in chemical sensors [7][8][9][10], biological sensors [11][12][13][14], and drug delivery devices [23][24][25].…”