Hydrogen effects on crystallinity, photoluminescence, and magnetization of indium tin oxide thin films sputter-deposited on glass substrate without heat treatment

Indium tin oxide (ITO) thin films were sputter deposited by using working gas containing hydrogen on glass substrate without any heat treatments. The films demonstrated X-ray diffraction due to polycrystalline ITO, blue-green photoluminescence (PL) due to oxygen defects in nano-structured ITO crystals, and paramagnetic behaviour in temperature dependence of magnetization overlapped with diamagnetic signal from the substrate. The carrier density n of the films was of the order of 10 20 cm -3 , and varied as an inverse of V-character with the hydrogen concentration [H] in the gas. The n value peaked at [H] = 1%. Spectral features at ≈430 and ≈470 nm of the PL emission were invariant with [H]. The order of the density of electrons N with spins obeying the Curie law was 10 23 cm -3 , and the variation in N with [H] was almost parallel to that in n with [H].