Theoretical characterization of carrier compensation in P-doped diamond

Based on the electron–hole recombination ratio (the number of electron–hole recombination in unit time and volume), we have examined several P complexes surrounded with vacancy (V) or H to explore the effect of carrier compensation on the electronic properties in P-doped diamond by first-principle calculations. Our calculated results show that the monovacancy complex P–V–H is not a valid recombination center in P-doped diamond, in which case electron cannot be recombined and thus donor cannot be compensated. However, the level in the band gap introduced by the divacancy complex P–2V–2H is a valid recombination center, which accelerates the electron–hole recombination at high ratio. For the trivacancy complex P–3V, three levels are introduced near the middle of the band gap, which may serve as more valid recombination centers than others. In this case, the electron–hole recombination ratio enhances successively, namely, the compensator density increases continuously too. In addition, the electronic properties of the P-related complexes in negative charge states are similar with those of neutral charge states. The study may explain well the experimental results and be useful for the further experiment research.