Analytical Formulation of Incremental Electrical Conductivity in Semiconductors arising from an Accumulation Space‐Charge Layer

Abstract

Analytic expressions are derived which relate the incremental electrical conductivity in an accumulation layer on a semiconductor to the concentration of surface ions. The theory is checked both by comparing the predicted results with published graphs which were obtained by numerical integrations, and by evaluating three separate sets of experimental data on different semiconducting materials. The data of Weller and Voltz for the effect of oxygen adsorbed on Cr2O3 do not fit the assumptions of the theory, since their particles are too small. The data of Smith for oxygen adsorbed on CuO, and the data of Molinari et al. for hydrogen on ZnO indicate that the observed trends are all in the proper direction and of the proper magnitude to support this work, but they are not of sufficient precision to support these derivations conclusively. Although a definitive quantitative experimental check remains to be done, the reasonableness of the derivation has been established.