The scarcity and noble indium and platinum (Pt) are important elements in photoelectric
nanomaterials. Therefore, development of low cost alternative materials to meet different
practical applications is an urgent need. Two-dimensional (2D) layered graphene (GE)
with unique physical, mechanical, and electrical properties has recently drawn a great
deal of attention in various optoelectronic fields. Herein, the large scale (21 cm
× 15 cm) high-quality single layer graphene (SLG) and multilayer graphene on a flexible
plastic substrate PET were controllably prepared through layer-by-layer (LBL) transfer
using the thermal release adhesive transfer method (TRA-TM). Transmission and antibending
performance based on PET/GE were superior to traditional PET/ITO. The square resistance
of a nine-layer graphene electrode reached approximately 58 Ω. Combined with our newly
developed and highly effective Fe3O4@RGO (reduced graphene oxide) catalyst, the power
conversion efficiency of the dye-sensitized solar cell (DSC) using flexible PET/GE
conductive substrate was comparable to that of the DSC using the PET/ITO substrate.
The desirable performance of PET/GE/Fe3O4@RGO counter electrodes (low-cost indium-
and platinum-free counter electrodes) is attributed to the interfacial compatibility
between 2D graphene composite catalyst (Fe3O4@RGO) and 2D PET/GE conductive substrate.
In addition, DSCs that use only PET/GE (without Fe3O4@RGO catalyst) as counter electrodes
can also achieve a photocurrent density of 6.30 mA cm(-2). This work is beneficial
for fundamental research and practical applications of graphene and graphene composite
in photovoltaics, photocatalytic water splitting, supercapacitors.