Extremely Sensitive Dependence of SnOx Film Properties on Sputtering Power

Abstract

An extremely sensitive dependence of the electronic properties of SnOx film on sputtering deposition power is discovered experimentally. The carrier transport sharply switches from n-type to p-type when the sputtering power increases by less than 2%. The best n-type carrier transport behavior is observed in thin-film transistors (TFTs) produced at a sputtering power just below a critical value (120 W). In contrast, at just above the critical sputtering power, the p-type behavior is found to be the best with the TFTs showing the highest on/off ratio of 1.79 × 104 and the best subthreshold swing among all the sputtering powers that we have tested. A further increase in the sputtering power by only a few percent results in a drastic drop in on/off ratio by more than one order of magnitude. Scanning electron micrographs, x-ray diffraction spectra, x-ray photoelectron spectroscopy, as well as TFT output and transfer characteristics are analyzed. Our studies suggest that the sputtering power critically affects the stoichiometry of the SnOx film.

High Performance Complementary Circuits Based on p-SnO and n-IGZO Thin-Film Transistors

“…The extracted total interface trap density was 6.41 × 10 12 cm −2 ·eV −1 , which is comparable with the values found in other studies [26]. The extracted total interface trap density of the SnO TFT was found to 1.03 × 10 13 cm −2 ·eV −1 , which is typical for SnO TFTs [12,27] but still much higher than the value obtained in the IGZO TFT. This might be due to the polycrystalline structure and the multi-phases in the SnO active layer [2,15].…”

Organic and inorganic passivation of p-type SnO thin-film transistors with different active layer thicknesses

“…Among the reported p-type oxide semiconductors, SnO is considered as one of the most promising due to its native p-type conductivity, high mobility, good stability and reproducibility [4][5][6][7][8][9][10]. The valence band maximum of SnO is composed by the hybridization of O 2p and delocalized spherical Sn 5s orbitals, thus leading to a small hole effective mass and relatively high mobility [5,11].…”

Scalable Fabrication of Stable High Efficiency Perovskite Solar Cells and Modules Utilizing Room Temperature Sputtered SnO2 Electron Transport Layer

“…For example, in the hydrothermal synthesis of SnO x from SnCl 2 precursor, an O 2 ‐deficient atmosphere leads to p‐type SnO dominated products. [26b] Using sputtering deposition, a slight change of sputtering power may change the as‐prepared thin film from n‐type to p‐type . When changing the reactive environment from Ar gas to H 2 gas, the SnO concentration also increases.…”