CDS-PBS HETEROJUNCTIONS

Heterojunctions between n-type CdS and p-type PbS were prepared by chemical deposition of PbS films on CdS single crystals. The PbS films were found to grow epitaxially on CdS crystals. The cubic (111) plane of PbS was parallel to the hexagonal (002) plane of CdS and the cubic (220) plane to the hexagonal (110) plane. The heterojunctions showed a marked photovoltaic effect and distinct rectifying characteristics. The maximum open circuit voltage obtained was 0.4V under irradiation with a tungsten lamp at 0.3 w/cm2. The spectral sensitivity of the photovoltaic effect showed a sharp maximum at the absorption edge of CdS and a flat plateau extending toward long wavelengths as far as lμ. The junction capacitance at zero bias and diffusion voltage were measured to be 10 ~ 30 nF/cm2 and 0.4V, respectively. From these results the energy band diagram was constructed for the heterojunction. © 1969, The Electrochemical Society, Inc. All rights reserved.