Typical XRD patterns for (pure ), 0.03, 0.4, and 0.5 films with (a) and (b) . is defined as an angle between film surface and diffractometer plane.
Lattice spacings ( and ) and cell volume as functions of Nb content .
Optical resistivity spectra at room temperature as functions of for . Solid lines denote the results of linear least-squares fitting.
Effective mass of as a function of carrier concentration . Circles denote optical mass derived from , and solid line is the result of curve fitting [Eq. (2)]. Dashed line shows the static effective mass calculated from Eq. (3).
Mobility vs temperature plots for (a) , (b) , and (c) films. Circles denote the experimentally observed Hall mobility. Solid line indicates the total mobility obtained by least-squares fitting. Dotted and dashed lines show and , respectively.
Temperature-independent component of mobility as a function of measured Nb content . Circles denote experimental . Solid, dotted, and dashed curves indicate , , and , respectively, obtained by fitting Eqs. (7) and (8) to experimental .
Mobility at as a function of measured Nb content . Circles denote the experimentally observed Hall mobility . Dashed, dotted, chain, and two-dot chain curves represent , , , and components, respectively, calculated using the fitting parameters in Table I. Corresponding total mobility is also demoted by a solid curve.
Optically derived mobility (closed circles) and Hall mobility (closed triangles) as functions of Nb content .
Nominal and measured Nb contents , carrier concentration , neutral impurity concentration , optical effective mass , phonon scattering enhancement factor , phonon frequency , grain size , trap density in grains , and temperature-independent component of mobility of anatase films. All parameters were estimated from the transport data at .
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