Novel p-type conductivity in SnO2 thin films by Mg doping

The effect of an Mg concentration on the structural, optical, and electrical properties of Mg-doped SnO2 transparent thin films that were deposited on glass substrates by electron beam evaporation was studied. X-ray diffraction patterns showed the deterioration of the crystallinity of the samples with increasing Mg concentration. The optical transmittance of the films exceeded 83% in the visible region. The band gap of the samples ranged from 3.49 to 3.78 eV. Hall-effect results indicated that p-type conductivity dominated when the acceptor dopant (Mg) concentration in the sample was below 4%. First-principles calculations based on density functional theory showed that the electronic properties were influenced by Mg concentration. When Mg content was 3%, the sample exhibited the highest hole concentration (8.24 × 1018 cm−3).