Enhancement of donor ionization in phosphorus-doped n-diamond

In order to explore a possibility for controlling an electron concentration in phosphorus-doped n-diamond, electron and ionized-donor concentrations in n-diamond/cBN and n-diamond/AlN heterojunctions are analyzed by self-consistently solving Poisson and Schrödinger equations. Although the electron concentration is an order of 1011 cm−3 at room temperature for single n-diamond with a donor concentration of 5 × 1018 cm−3 and a compensation ratio of 0.01, a modulation-doping technique predicts to provide full ionization of phosphorus donor in the n-diamond/cBN heterostructure and generation of an electron concentration larger than 1018 cm−3 at room temperature.