Post-deposition annealing effects on the transparent conducting properties of anatase Nb:TiO₂ films on glass substrates

다국어 초록 (Multilingual Abstract)

Five percent Nb-doped TiO<SUB>2</SUB> (Nb:TiO<SUB>2</SUB>) films on glass substrates were prepared with pulsed laser deposition in 10mTorr at room temperature, and then, they were annealed at various temperatures from 250 to 550<SUP>o</SUP>C in vacuum (<10<SUP>-5</SUP>Torr). The X-ray diffraction data suggest that the as-prepared amorphous Nb:TiO<SUB>2</SUB> film on glass was transformed to the (101) oriented anatase phase above ~350<SUP>o</SUP>C. For the anatase Nb:TiO<SUB>2</SUB> samples, the temperature dependence of the resistance exhibited a metallic behavior. As the post-deposition annealing temperature increased up to 550<SUP>o</SUP>C, the resistivity (~3.9x10<SUP>-4</SUP>Ωcm) was minimum at 450<SUP>o</SUP>C while the Hall mobility (2.6cm<SUP>2</SUP>/(Vs)) and carrier density (4.7x10<SUP>21</SUP>cm<SUP>-3</SUP>) were maximum. The optical transmittance in the visible light range was about 70-80%, and the optical band gaps gradually decreased from 3.64 to 3.28eV as the post-deposition annealing temperature increased.