High electron mobility thin-film transistor enabled by solution-deposited low-
dimensional metal oxide heterointerface channels
Max Grell* and Thomas D. Anthopoulos
Department of Physics and Centre for Plastic Electronics
Imperial College London, Blackett Laboratory,
London, SW7 2BW (United Kingdom)
*Corresponding authors
Thin-film transistors based on metal oxide semiconductors represent a promising technology
for a range of existing as well as emerging applications. This is due to their combination of
high carrier mobility, optical transparency, mechanical flexibility, and their potential for low-
temperature processing. Widespread commercialization of metal oxide thin-film transistors,
however, demands further improvement of key performance indicators such as charge-carrier
mobility
1
. Atomically flat interfaces between semiconducting oxides demonstrate a wide
range of novel phenomena, such as 2-dimensional charge transport characteristics
2
, strongly
correlated charge carriers
3
, highly conducting and even superconducting channels
4
. Field-
effect devices with such interfaces demonstrate charge-carrier mobilities orders of magnitude
greater than the constituent semiconducting oxides, and are hoped to compete with traditional
group IV or II-V semiconductors for use in the next-generation of high-performance
electronics.
Here we present our latest findings toward high performing electron transporting thin-film
transistors based on low-dimensional metal oxide heterointerface channels. Solution based
deposition techniques at low temperatures (<250°C), under atmospheric conditions without
any costly vacuum equipment, have been employed to create bilayer thin-film transistors with
electron mobilities in excess of 50 cm
2
V
-1
s
-1
. Deposition techniques include spray-pyrolysis
and spin-coating and semiconducting oxides include In
2
O
3
and ZnO from a variety of
precursor solutions. Results will be presented illustrating how these materials and techniques
can be optimised toward high mobility transistors. Analysis of the charge transport processes
in these oxide heterointerfaces using Hall effect techniques will also be presented, along with
the impact of extrinsic doping on the devices’ operating characteristics. This work presents a
promising line of research toward the next generation of high-performing, low-cost and large-
area electronics.
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2.
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Nature
427,
423–
426 (2004).
3.
Mannhart, J. & Schlom, D. G. Oxide interfaces--an opportunity for electronics.
Science
327,
1607–1611 (2010).
4.
Gozar, a.
et al.
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Nature
455,
782–785 (2008).
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