Electronic, magnetic and optical properties of C, N-doped TiO_2 anatase: A hybrid density functional study

摘要

We address the electronic, magnetic and optical properties of two non-metal dopants nitrogen and carbon. We have considered two configurations (i) Nitrogen as substitution and interstitial dopants (N_s, N_i) (ii) Carbon as substitution and interstitial dopants (C_i, C_i) in anatase TiO_2. To obtain a realistic description of the electronic structure, magnetic and optical properties the performance of the exchange-correlation functional is carefully analyzed, and validated with available experimental results. We have obtained that C_s and N_s occupy a magnetic moment of 2 and 1 μB, respectively. We report here using state-of-the-art hybrid density-functional theory the abrupt change of magnetic moment from C_s to C_i. We have found that C_i is non-magnetic i.e., 0 μB while nitrogen always possesses a magnetic moment of 1 μB. In addition, our results reveal that N_s and C_s give rise to visible light absorption in TiO_2 anatase, which is in agreement with the experimental results.