Electrical-Transport Measurements on Synthetic Semiconducting Diamond

Abstract

Four-probe electrical-conductivity measurements have been made on a series of General Electric aluminum-doped and nominally boron-doped synthetic semiconducting diamonds in the temperature range 223 to 323°K, and the results compared with those obtained from a natural semiconducting diamond (type IIb). These results, together with those obtained from optical-absorption, recombination-radiation, and chemical-impurity measurements on the same set of specimens, show that the same acceptor center, namely aluminum, is responsible for the semiconducting properties of both natural diamond and synthetic semiconducting diamond presently available. The large range of activation energies reported by other workers is considered to be due to the onset of impurity conduction at progressively higher temperatures with increasing concentrations of neutral acceptor centers.