First-principles study on the electronic, optical, and transport properties of P-type transparent conductive oxides Sn₂NbxTa2-xO₇ (x = 2, 1.5, 1, 0.5, 0)

The paper uses the first-principles methods to study the structure, stability, electronic properties, conductivity types, transport properties, and optical properties of Sn 2 Nb x Ta 2-x O 7 (x = 2, 1.5, 1, 0.5, 0). Using the HSE06 method to calculate the band structure, it is found that Sn 2 Nb x Ta 2-x O 7 has wide band gaps of 2.002 eV, 2.052 eV, 2.064 eV, 2.305 eV, and 2.558 eV, respectively. The branch point energy (BPE) and ionization energy criteria determine that Sn 2 Nb x Ta 2-x O 7 are more suitable for studying P-type properties, so we calculated its hole mobility. The hole mobility in the [001] direction of x = 2, 1.5, 1, 0.5, 0 is 39.60 cm 2 V −1 s −1 , 749.31 cm 2 V −1 s −1 , 762.59 cm 2 V −1 s −1 , 106.72 cm 2 V −1 s −1 , 16.06 cm 2 V −1 s −1 , respectively. Meanwhile, Sn 2 Nb x Ta 2-x O 7 has good visible light transmittance. Both optical and transport properties indicate that they are promising P-type transparent conductive oxides.