Thermopower of parallel conducting structures

Thermopower measurements can be a powerful tool for characterizing structures with parallel conducting layers such as intentional heterostructures or p-n junctions (such as solar cells) or materials with unintentional surface accumulation or inversion layers (such as InN, InAs, In$_{2}$O$_{3}$, and CdO). In such cases, the macroscopically observed Seebeck coefficient depends on the contributions of various layers and the nature of the internal junctions between them. Thermopower measurements of such structures in group IV and III-V materials are presented and analyzed in terms of a parallel conduction model in which the observed Seebeck coefficient depends on the conductance-weighted Seebeck coefficients of each layer.