(Invited) Solution Processed Oxide Thin Film Transistors

We have developed thin-film-transistors (TFTs) manufactured by a solution processing of the gate insulators and the active material. Oxide insulators, such as aluminum oxide, hafnium oxide, or zirconium doped aluminum oxide represent a method to achieve high performance and low power consuming TFTs. Along with amorphous indium gallium zinc oxide ( a-IGZO), other oxide semiconductors have been studied. Solution processing offers the opportunity to test various materials quickly with low capital investment. We studied poly-crystalline materials, such as indium oxide (In₂O₃), and tin oxide (SnO₂), or amorphous oxides such as indium zinc tin oxide (IZTO).

We have developed inket-printed TFTs at the maximum process temperature of 300^oC. Inkjet-printed polycrystalline InOx TFTs have mobilities of 60cm²/Vs, and were used in unipolar inverters. SnOx TFTs, show a dependence on the solution concentration, and the mobility can reach ~70cm²/Vs. On the other hand, amorphous IZTO TFTs showed the highest mobility of ~100cm²/Vs by the careful control of the inkjet process.

References

C. Avis and J. Jang, J. Mater. Chem., 21, 10649-10652, 2011

C. Avis and J. Jang, Jap. J. Appl. Phys., 2011, 50, 01BG03, 2011

C. Avis and Jin Jang, Electrochem. Solid-State Lett., 4, J9-J11, , 2011

Y. G. Kim, C. Avis and J. Jang, ECS Solid-State Lett., 1, Q23-Q25, 2012

C. Avis, Y. G. Kim, and J. Jang, J. Mater. Chem., 22, 17415–17420, 2012

Y. G. Kim, C. Avis, and J. Jang, J. Disp. Tech., accepted, 2014

Figure 1: transfer characteristics of IZTO TFT.