Amorphous-porous silicon heterojunction for gas sensor application

In this work we studied the compatibility of amorphous thin film technology with the porous silicon in case of large area applications like gas sensor s. We found that thin amorphous silicon layer growth on porous silicon subs trates preserves the room temperature photoluminescence of porous material. Also amorphous-porous silicon heterojunction shows a good rectifying behav iour. Those properties, correlated with the porous silicon sensitivity to t he gas environments, can be effectively used to realise heterojunction diod es whose current voltage characteristics are modified by the gas reactivity on the porous surface. Sensitivity of those devices and response time to d ifferent gas exposure have been investigated.