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The Burstein-Moss shift and band gap narrowing of sputtered indium-doped zinc oxide (IZO) thin films are investigated as a function of carrier concentrations. The optical band gap shifts below the carrier concentration of 5.61 × 1019 cm-3 are well-described by the Burstein-Moss model. For carrier concentrations higher than 8.71 × 1019 cm-3 the shift decreases, indicating that band gap narrowing mechanisms are increasingly significant and are competing with the Burstein-Moss effect. The incorporation of In causes the resistivity to decrease three orders of magnitude. As the mean-free path of carriers is less than the crystallite size, the resistivity is probably affected by ionized impurities as well as defect scattering mechanisms, but not grain boundary scattering. The c lattice constant as well as film stress is observed to increase in stages with increasing carrier concentration. The asymmetric XPS Zn 2p3/2 peak in the film with the highest carrier concentration of 7.02 × 1020 cm-3 suggests the presence of stacking defects in the ZnO lattice. The Raman peak at 274 cm-1 is attributed to lattice defects introduced by In dopants.

Surface phonon polariton (SPP) mode of wurtzite structure AlxGa1−xN (0⩽x⩽1) thin films is investigated experimentally and theoretically. The influences of the alloy composition x on the position and the line width of SPP mode are reported. The results showed that the SPP absorption peak exhibits one-mode behavior and is subjected to broadening as x is increased. Reasonable agreement between the experimental and the theoretical results is also obtained. Finally, the composition dependence of the SPP mode with bowing parameter of −72.5cm−1 is determined.

The surface phonon polariton (SPP) mode of aluminum nitride (AlN) thin film grown on sapphire substrate is investigated experimentally and theoretically. For the experimental study, p-polarized infrared attenuated total reflection measurements are performed. A strong absorption dip which corresponds to the SPP mode of AlN thin film is clearly observed at 839.0cm−1. For the theoretical study, the surface-polariton dispersion curve of the AlN thin film has been simulated. Finally, the experimental and theoretical values of the SPP mode are compared. The results revealed that the uncertainty between the theoretical and experimental SPP values is less than 2%.

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