ELECTRICAL PROPERTIES OF SINGLE-CRYSTAL GALLIUM PHOSPHIDE DOPED WITH ZINC

Hall measurements have been made on epitaxially grown, zinc-doped gallium phosphide, from which the gallium arsenide substrate had been removed. The measurements were made in the temperature range from 300°to 4°K on samples whose room-temperature carrier concentration varied from 7×10 15 to 7×1018 cm-3. Using both van der Pauw and conventional Hall techniques on those samples which show a high degree of compensation, the variation of the ionization energy of zinc with concentration was determined. Room-temperature hole mobility varied from 60 to 100 cm2·V-1·sec-1. These observed hole mobilities are in good agreement with the calculated values of mobility due to reduced scattering by acoustical and optical phonons, and are shown to be too small to be accounted for by the mechanism of impurity scattering below 100°K. Resistivity measurements made in the temperature range 77°-4.2°K show that in the impurity band conduction range, gallium phosphide behaves in a manner similar to impure germanium. © 1968 The American Institute of Physics.