Published online by Cambridge University Press: 01 February 2011
Among many doping issues of diamond semiconductors, establishment of a shallow n-type impurity is a very important and yet challenging subject. Although both nitrogen (N) and hydrogen (H) are omnipresent impurities in diamond, they create only deep half-filled states in the energy gap. In this study, we present a theoretical proposal of a mechanism that makes N donors in diamond as shallow as possible. A complex of two adjacent substitutional N atoms with H sitting between the N atoms, an N-H-N defect, has a donor level approximately 1 eV shallower than of an isolated substitutional N defect.