Dependence of the conductivity of porous silicon layers on the carrier-transport direction

An investigation into carrier-transport mechanisms in mesoporous silicon layers for the cases of transport along the layer surface (perpendicularly to silicon columns) and perpendicularly to the layer surface (along silicon columns) is presented. It is established that the conductivity measured along the layer surface is much lower than the conductivity measured perpendicularly to the surface. It is concluded from analysis of the temperature and frequency dependences of the conductivity that the carrier-transport mechanisms are different in the cases under consideration (along and perpendicularly to the surface).