Photoconductive Behavior of Lead Sulfide Films. Volume 1.

摘要

The structure, chemical composition, and photoelectronic properties of chemically deposited PbS films have been investigated in relationship to variation in the concentration of oxidant used in the deposition. Structure and photoelectronic properties in the PbS film change as the concentration of oxidant is varied. Concomitant variations in the average chemical composition of the films are minor. It was found that the dependence of carrier density and mobility on temperature is divided into low and high temperature regions with distinct activation energies. The principal effect of photoexcitation is to increase the carrier density. Films produced without the use of oxidants are relatively insensitive. The primary electronic properties of PbS films may be described in terms of sensitizing centers located 0.23 eV below the conduction band, and in terms of intergrain barriers which limit the effective mobility. The intergrain barriers play no essential role in the photoconductive process. PbS films deposited from baths containing no oxidant lack the sensitizing centers.