Local environment of Boron impurities in porous silicon and their interaction withNO2molecules

An integrated CMOS sensing chip for NO2 detection

“…Changes in the conductivity of over one order of magnitude have been observed upon exposure of PS, obtained from heavily p-type doped substrates, to hundreds ppb of NO 2 [22,23]. Such large changes have been explained by suggesting that the acceptor function of boron dopants, usually inhibited in PS, is reactivated by NO 2 adsorption [24,25].…”

NO2 adsorption effects on p+–n silicon junctions surrounded by a porous layer

“…As far as PS is concerned, it is well known from literature data that NO 2 interaction with PS strongly affects the electrical conductivity of PS layers, even at room temperature [23]. This effect is commonly exploited for PS-based NO 2 sensor fabrication.…”

A new route to the surface functionalisation of porous silicon

“…Etch stops have been introduced in every cycle in order to replenish the solution inside the pores so avoiding the vertical porosity gradient. At the end of anodisation programmed in order to obtain a 40 m thickness layer, the PS membrane has been detached by means of a high current pulse and deposited on p-type c-Si (3-6 cm resistivity) [15]. Subsequently, the sample has been introduced into a quartz vacuum cell, with KBr windows and connected to a vacuum frame permitting operations under controlled atmosphere.…”