GALLIUM PHOSPHIDE DOUBLE-EPITAXIAL DIODES

The external quantum efficiency of red EL emission in GaP diodes is studied as a function of doping in the p layer. A standardized procedure is used, consisting of liquid phase epitaxial growth of an n layer, followed by similar growth of the p layer. It is found that efficiencies up to 1.4% result from optimizing the Zn and O additions to the p melt, but that efficiencies as high as 3.4% can be obtained if the p melts are compensated by the addition of Te. Arguments are presented showing that a residual donor, probably sulfur, accounts for compensation effects in diodes made by an earlier process. Some other factors which may influence the efficiency are also discussed. © 1969, The Electrochemical Society, Inc. All rights reserved.