Synthesis of N-type semiconductor diamonds with sulfur, boron co-doping in FeNiMnCo-C system at high pressure and high temperature**Project supported by the National Natural Science Foundation of China (Grant No. 11604246), China Postdoctor Science Foundation (Grant No. 2016M592714), Professional Practice Demonstration Base for Professional Degree Graduate in Material Engineering of Henan Polytechnic University, China (Grant No. 2016YJD03), the Education Department of

Abstract

A series of diamonds with boron and sulfur co-doping were synthesized in the FeNiMnCo-C system by temperature gradient growth (TGG) under high pressure and high temperature (HPHT). Because of differences in additives, the resulting diamond crystals were colorless, blue-black, or yellow. Their morphologies were slab, tower, or minaret-like. Analysis of the x-ray photoelectron spectra (XPS) of these diamonds shows the presence of B, S, and N in samples from which N was not eliminated. But only the B dopant was assuredly incorporated in the samples from which N was eliminated. Resistivity and Hall mobility were 8.510 Ω·cm and 760.870 cm2/V·s, respectively, for a P-type diamond sample from which nitrogen was eliminated. Correspondingly, resistivity and Hall mobility were 4.211×105 Ω·cm and 76.300 cm2/V·s for an N-type diamond sample from which nitrogen was not eliminated. Large N-type diamonds of type Ib with B–S doping were acquired.