Graphene as transparent conducting electrodes in organic photovoltaics: studies in graphene morphology, hole transporting layers, and counter electrodes

Publication Type:

Journal Article

Source:

Nano Lett., ACS Publications, Volume 12, Issue 1, p.133-140 (2012)

ISBN:

1530-6984

Keywords:

2012, 2013 and earlier

Abstract:

In this work, organic photovoltaics (OPV) with graphene electrodes are constructed where the effect of graphene morphology, hole transporting
layers (HTL), and counter electrodes are presented. Instead of the
conventional poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate)
PEDOT:PSS HTL, an alternative transition metal oxide HTL (molybdenum oxide
(MoO(3))) is investigated to address the issue of surface immiscibility
between graphene and PEDOT:PSS. Graphene films considered here are
synthesized via low-pressure chemical vapor deposition (LPCVD) using a
copper catalyst and experimental issues concerning the transfer of
synthesized graphene onto the substrates of OPV are discussed. The
morphology of the graphene electrode and HTL wettability on the graphene
surface are shown to play important roles in the successful integration of
graphene films into the OPV devices. The effect of various cathodes on the
device performance is also studied. These factors (i.e., suitable HTL,
graphene surface morphology and residues, and the choice of well-matching
counter electrodes) will provide better understanding in utilizing
graphene films as transparent conducting electrodes in future solar cell
applications.