Lateral organic bilayer heterojunction photoconductors

Publication Type:

Journal Article

Source:

Appl. Phys. Lett., AIP Publishing, Volume 93, Issue 6, p.063305 (2008)

ISBN:

0003-6951

Keywords:

2008, 2013 and earlier

Abstract:

We demonstrate a two-terminal, lateral organic bilayer photoconductor that generates an external quantum efficiency of ( 12 ± 1 ) % , with an
internal quantum efficiency of ( 140 ± 2 ) % indicative of
photon-to-electron conversion gain. The photoconductor incorporates a
heterojunction between N , N ′ -bis(3-methylphenyl)- N , N ′ -diphenyl- 1
, 1 ′ -biphenyl- 4 , 4 ′ -diamine (TPD) and
3,4,9,10-perylenetetracarboxylic bisbenzimidazole (PTCBI).
Excitonsgenerated with photoexcitation of PTCBI dissociate at the
PTCBI/TPD interface and raise the charge carrier concentration in TPD,
increasing device conductance. The exposed top surface enables interaction
with chemical analytes in the environment, motivating the use of the
photoconductor as a chemical sensor that transduces chemical signals into
amplified changes in the electrical response.