tesi R. Miscioscia.pdf - EleA@UniSA

20 Working Principles
1.3 Brief on working regimes of OTFTs
In this section, a quick overview of operating regions for
modeled OTFT devices is given to introduce terms and concepts
which will be utilized in the next chapters.
Linear region
In the linear regime, a film of mobile charge is formed at the
interface between the insulator and the semiconductor material.
figure 4: OTFT working in the linear region representation; the purple zone is a simplified view of
the mobile charge in the channel.
In the hypothesis of VDS≤VG+V0, we can consider valid the GCA
and uniform the electric field component E x along the D/S direction.
Then, we can approximate it as: Ex ≈VDS/L and neglect the injection
current contribution which is bound to QDS and to the difference ( Ex
(L) - x E (0))2 , then the channel current can be approximated by eq. 20
W
L
eq. 20 I μ
C ( ( V + V ) ⋅V
)
DS = n ins GS 0
DS