Characteristics of n- and p-type dopants in 1T-HfS2 monolayer

We explored the characteristics of n- and p-type impurities by means of group V and VII atoms substituting sulfur in 1T-HfS2 monolayer using the first-principles calculation. Numerical results show that the formation energy increases with the increasing impurity atom size for each considered doping case, and the formation energy calculations also indicate that it is energy favorably and relatively easier to incorporate these atoms into the HfS2 under Hf-rich experimental conditions. Meanwhile, with increasing atomic size, the transition energy levels increase for group V atoms substitution. While the transition energy levels decrease with increasing atomic size for group VII atoms substitution. The calculations of the transition energy level indicate that the N-doped HfS2 monolayer has the lowest formation energy and the shallowest transition level among the p-doped HfS2 monolayer systems. (C) 2016 Elsevier B.V. All rights reserved.