David S. Eddy

Analysis of photojunctions formed by diffusing copper into insulating cadmium sulfide crystals

A study of the observed photovoltaic, photorectification, and field effect modulation properties of junctions formed by diffusing copper into photoconductive, dark‐insulating CdS crystals shows that two potential barriers are produced, one at the surface, the other in the crystal bulk. A transition from a double space charge dipole to a single separated dipole occurs at a reverse bias of less than 1 v. A corresponding transition from a primary to a secondary photocurrent process results. Values for the drift mobility of holes ranging from 10−5–10−2 cm2/v‐sec were derived from field effect measurements and found to be proportional to illumination intensity at the infrared quenching wavelengths.

Ion Drift Equilibrium in a Semiconductor

If the impurity ions in a semiconductor are subjected to an electric field, an equilibrium distribution can result when the sum of drift and diffusion fluxes are balanced throughout the system. A simple solution for this distribution results for a one‐ion system in which intrinsic carriers are neglected. The solution agrees with experimental results for indium ions in cadmium sulfide based on capacitance‐voltage measurements.