Abstract
We report an electron-transport material; 2,5-dibenzthiazolyl thiophene (TBZT) characterized using the photogenerated time-of-flight technique, which shows a weak electric-field-dependent electron mobility, typically of the order of
1.21
×
10
−
4
cm
2
∕
V
s
at
2.5
×
10
5
V
∕
cm
, two orders of magnitude higher than the
Alq
3
complex. This enhanced carrier mobility is facilitated by the excited-state configuration of the molecule as verified by the AM1-CI semiempirical calculations in the anionic form. We show the effect of high mobility electron transport on a bilayer electroluminescent device, ITO∕TPD∕ZBZT∕TBZT
(
10
nm
)
∕
Al
, using bis [
(
2
-
(
2
′
-
hydroxyl
phenyl
)
benzthiazolate] zinc (II) complex as the emissive layer which resulted in a
25
-
nm
significant shift in the recombination zone and an improved current-voltage characteristics by a factor of two.