Effects of intergranular capacitance and resistance dispersion on polycrystalline semiconductor impedance

BUONO, C.; URIZ, A.J.; ALDAO, C.M.

SOLID STATE IONICS

ELSEVIER SCIENCE BV

Año: 2019 vol. 343

0167-2738

In the present work we focused on the effects, often disregarded, of the intergranular barrier fluctuations on thetotal impedance of polycrystalline structures. These fluctuations come from the discreteness nature and randomdistribution of ionized donors at the polycrystal, which are responsible of forming the intergranular barriers.Firstly, we used a numerical model that takes into account the point character of the involved donors and foundthat resistances and capacitances present distributions that become narrower with the grain size. Secondly, webuilt a bricklayer model with capacitances and resistances taken from the found distributions and calculated thetotal impedance, focusing on tin oxide as an example. We found the total polycrystal capacitance and resistancedependence on the specific dispersions of intergranular capacitances and resistances.