Title
Charge transport in amorphous InGaZnO thin-film transistors
Author
Germs, W.C.
Adriaans, W.H.
Tripathi, A.K.
Roelofs, W.S.C.
Cobb, B.
Janssen, R.A.J.
Gelinck, G.H.
Kemerink, M.
Publication year
2012
Abstract
We investigate the mechanism of charge transport in indium gallium zinc oxide (a-IGZO), an amorphous metal-oxide semiconductor. We measured the field-effect mobility and the Seebeck coefficient (S=ΔV/ΔT) of a-IGZO in thin-film transistors as a function of charge-carrier density for different temperatures. Using these transistors, we further employed a scanning Kelvin probe-based technique to determine the density of states of a-IGZO that is used as the basis for the modeling. After comparing two commonly used models, the band transport percolation model and a mobility edge model, we find that both cannot describe the full properties of the charge transport in the a-IGZO semiconductor. We, therefore, propose a model that extends the mobility edge model to allow for variable range hopping below the mobility edge. The extended mobility edge model gives a superior description of the experimental results. We show that the charge transport is dominated by variable range hopping below, rather than by bandlike transport above the mobility edge. © 2012 American Physical Society.
Subject
Mechatronics, Mechanics & Materials
HOL - Holst
TS - Technical Sciences
High Tech Systems & Materials
Physics
Industrial Innovation
To reference this document use:
http://resolver.tudelft.nl/uuid:0185b3b8-0338-4571-8d70-a01a01967697
TNO identifier
465833
ISSN
1098-0121
Source
Physical Review B - Condensed Matter and Materials Physics, 86 (15)
Article number
155319
Document type
article