Papers by Author: Satoshi Koizumi

Abstract: We have succeeded to grow high quality phosphorus doped n-type diamond thin films on {111} diamond substrates. Although the ionization energy of phosphorus donor is large (0.57 eV), the n-type conductivity is clearly observed by Hall measurements. The Hall mobility is as high as 660 cm2/V-sec at room temperature. In this paper, current status of n-type diamond research are mentioned mainly focused on the growth of high mobility n-type diamond and its electrical properties. High quality diamond growth has been carried out by surface pre-treatment of diamond substrate. The Hall measurements performed in a wide temperature range gives detailed information about the n-type conductivity nature.

Abstract: The n-type doping of diamond with phosphorus suffers from defects reducing the electron mobilities and inducing some degree of compensation. In addition, the relatively high ionization energy (0.6 eV) of phosphorus severely limits the electrical activity of the dopants. Here, we present two recent advances of the n-type doping of diamond. One is based on the significant reduction of the compensation ratio of highly compensated phosphorus-doped diamond by thermal annealings. The second one presents the possibility of converting p-type boron-doped diamond into n-type by deuterium diffusion and formation of deuterium-related shallow donors with ionization energy of 0.33 eV.