Details

Autor(en) / Beteiligte

• Benwadih, Mohammed
• Chroboczek, J. A.
• Ghibaudo, Gérard
• Coppard, Romain
• Vuillaume, Dominique

Titel

Non-Arrhenius conduction due to the interface-trap-induced disorder in X-doped amorphous In-X-Zn oxides thin-film transistors

Ist Teil von

• Journal of applied physics, 2015-02, Vol.117 (5)

Ort / Verlag

Melville: American Institute of Physics

Erscheinungsjahr

2015

Link zum Volltext

Quelle

Scitation (American Institute of Physics)

Beschreibungen/Notizen

• Thin film transistors, with channels composed of In-X-Zn oxides, IXZO, with X dopants: Ga, Sb, Be, Mg, Ag, Ca, Al, Ni, and Cu, were fabricated and their I-V characteristics were taken at selected temperatures in the 77 K < T < 300 K range. The low field mobility, μ, and the interface defect density, NST, were extracted from the characteristics for each of the studied IXZOs. At higher T, the mobility follows the Arrhenius law with an upward distortion, increasing as T is lowered, gradually transforming into the exp [-(T0/T)1/4] variation. We showed that μ(T, NST) follows μ0 exp[-Eaeff(T,NST)/kT], with T-dependent effective activation energy Eaeff(T, NST) accounts for the data, revealing a linear correlation between Eaeff and NST at higher T. Temperature variation of Eaeff(T, NST) was evaluated using a model assuming a random distribution of conduction mobility edge Ec values in the oxides, stemming from spatial fluctuations induced by disorder in the interface traps distribution. For a Gaussian distribution of Ec, the activation energy Eaeff(T, NST) varies linearly with 1/T, which accounts satisfactorily for the data obtained on all the studied IXZOs. The model also shows that Eaeff(T, NST) is a linear function of NST at a fixed T, which explains the exponential decrease of μ with NST.