Influence of annealing temperature on the optoelectronic properties of ITZO thin films

Abstract

In this work, the electrical conductivity and optical transparency of the In-Sn-Zn-O (ITZO) films annealed at different temperatures were investigated. The results show that the ITZO films transformed from amorphous phase to crystalline phase after annealed in the air. The transmittance of the films improves significantly and all exceed 88%. Meanwhile, the annealed ITZO films exhibit a significant enhancement in conductivity. In particular, ITZO film annealed at 650 °C has high electrical conductivity (∼4.94×10 2 S cm −1 ) and an excellent figure of merit (∼5.94×10 −4 Ω −1 ). Moreover, ITZO thin film transistors were prepared and their performance was tested. After annealing, the high electrical properties of the active layer make the gate regulation ability of the thin film transistors degrade. The annealed films with excellent optoelectronic properties can be applied to transparent electrodes.

High-mobility InSnZnO Thin Film Transistors via Introducing Water Vapor Sputtering Gas

“…The bandgap ( E g ) was determined by analyzing the horizontal intercept of the linear portion in the Tauc plot from Figure f. The E g of all the films range from 3.2 to 3.5 eV, consistent with the range of E g reported for conventional ITZO films. , It is evident from the figure that the E g of the no-water film is smaller than that of the with-water film at all T A . Prior studies report that in the same material, an increase in defects typically leads to a reduction in the bandgap. − However, the relationship between them is reverse in this work, as found in Figure e,f that the with-water films inhibit more band-tail and deep-level defects and demonstrate a larger E g at T A = 0, 200 °C.…”

“…The E g of all the films range from 3.2 to 3.5 eV, consistent with the range of E g reported for conventional ITZO films. 22,23 It is evident from the figure that the E g of the no-water film is smaller than that of the with-water film at all T A . Prior studies report that in the same material, an increase in defects typically leads to a reduction in the bandgap.…”

Effect of oxygen partial pressure on the performance of homojunction amorphous In-Ga-Zn-O thin-film transistors

“…With a steady increase in the oxygen partial pressure, it could lead to the growth of acceptor-like deep states, which can be considered as weakly bonded excess oxygen states (O°or O − ) [40]. The increasing accepter-like deep states will trap more electrons in the channel to form ionized stable O 2− states, thus the S.S turns to increase [13]. From the change of the S.S, it can be concluded that the S.S of the device can be optimized by varying the oxygen partial pressure.…”

“…In recent years, transparent-oxide-semiconductorbased transistors have emerged as promising alternatives to the aforementioned TFTs due to its high μ FE (>10 cm 2 V −1 s −1 ), small sub-threshold swing (S.S), low off current (I off ), good stability under electrical stress and low-temperature fabrication (<250 °C) [8]. A large number of oxide semiconductors have been developed for TFT applications, including amorphous zinc-tin oxide (a-ZTO) [9], amorphous indium-zinc oxide (a-IZO) [10], amorphous indium-galliumzinc oxide (a-IGZO) [11,12] and amorphous indium-tin-zinc oxide (a-ITZO) [13,14].…”