The electrical injection in porous silicon fabricated with heavily doped p-type silicon is very sensitive to NO 2. The known effect is an injection increase associated to NO 2. We show experimentally a strong correlation between two structural properties and the sensitivity of electrical injection to NO 2. The first property is the microstructure, i.e. the pore morphology at nm scale. A structure with straight, elongated pores shows large sensitivity, as opposed to a branching structure. The second property is the layer thickness, which determines the sign of the effect of NO 2. If the thickness is sufficiently low - of the order of few Urn - the injection in presence of NO 2 decreases, instead of increasing. © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Role of microstructure and layer thickness in porous silicon conductometric gas sensors
OTON NIETO, CLAUDIO JOSE;
2005-01-01
Abstract
The electrical injection in porous silicon fabricated with heavily doped p-type silicon is very sensitive to NO 2. The known effect is an injection increase associated to NO 2. We show experimentally a strong correlation between two structural properties and the sensitivity of electrical injection to NO 2. The first property is the microstructure, i.e. the pore morphology at nm scale. A structure with straight, elongated pores shows large sensitivity, as opposed to a branching structure. The second property is the layer thickness, which determines the sign of the effect of NO 2. If the thickness is sufficiently low - of the order of few Urn - the injection in presence of NO 2 decreases, instead of increasing. © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
