Dual Electrical Behavior of Multivalent Metal Cation-Based Oxide and Its Application to Thin-Film Transistors with High Mobility and Excellent Photobias Stability

作者：Yun Myeong Gu; Ahn Cheol Hyoun; Cho Sung Woon; Kim So Hee; Kim Ye Kyun; Cho Hyung Koun^*

来源：ACS Applied Materials & Interfaces, 2015, 7(11): 6118-6124.

DOI：10.1021/am5085836

• multivalent metal cation
• dual electrical property
• oxide semiconductor
• thin film transistor
• stability

The effect of multivalent metal cations, including vanadium(V) and tin (Sn), on the electrical properties of vanadium-doped zinc tin oxide (VZTO) was investigated in the context of the fabrication of thin-film transistors (TFTs) using a single VZTO film and VZTO/ZTO bilayer as channel layers. The single VZTO TFT did not show any response to the gate voltage (insulator-like behavior). On the other hand) the VZTO/ZTO bilayer TFT exhibited a typical TFT transfer characteristic (semiconducting behavior). X-ray photoelectron spectroscopy revealed that, in contrast to what is commonly true in many oxides, oxygen, vacancies (V-O) in VZTO did not provide a dominant contribution to the total carrier concentration, because the V-O peak area in the single VZTO film was 5.4% and reduced to 4.5% in VZTO/ZTO bilayer. Instead, Sn 3d(5/2) and V 2p(3/2) spectra suggest that the significant reduction in Sn and V ions is strongly related to the insulator-like behavior of the VZTO film. In negative-bias illumination tests and illumination tests with various photon energies, the VZTO/ZTO bilayer TFT had much better stability than the ZTO TFT. This result is attributed to the reduction of donor-like states (V-O) that can be positively ionized by blue and green illumination.

• 出版日期2015-3-25