The Effects of Gadolinium Incorporation Into Indium–Zinc–Oxide Thin-Film Transistors

We investigated the effects of gadolinium (Gd) incorporation into indium-zinc-oxide (IZO) thin-film transistors (TFTs) using radio-frequency cosputtering of IZO and Gd. A gadolinium-indium-zinc-oxide (Gd-IZO) TFT with 2.4 at.% Gd content had saturation-mode field-effect mobility, threshold voltage, and switching ratio (on current/off current) of 6.6 cm
²
V
^-1
s
^-1
, 1.04 V, and on the order of 10
⁷
, respectively, after thermal annealing at 250 °C. A Gd-IZO TFT with 2.4 at.% Gd content showed better switching performance and thermal stability than pure IZO TFTs due to stable ionic bond between Gd and O.