This
work presents an original synthesis of TiO
2
/graphene
nanocomposites using laser pyrolysis for the demonstration of efficient
and improved perovskite solar cells. This is a one-step and continuous
process known for nanoparticle production, and it enables here the
elaboration of TiO
2
nanoparticles with controlled properties
(stoichiometry, morphology, and crystallinity) directly grown on graphene
materials. Using this process, a high quality of the TiO
2
/graphene interface is achieved, leading to an intimate electronic
contact between the two materials. This effect is exploited for the
photovoltaic application, where TiO
2
/graphene is used as
an electron-extracting layer in n–i–p mesoscopic perovskite
solar cells based on the reference CH
3
NH
3
PbI
3–
x
Cl
x
halide
perovskite active layer. A significant and reproducible improvement
of power conversion efficiencies under standard illumination is demonstrated,
reaching 15.3% in average compared to 13.8% with a pure TiO
2
electrode, mainly due to a drastic improvement in fill factor. This
beneficial effect of graphene incorporation is revealed through pronounced
photoluminescence quenching in the presence of graphene, which indicates
better electron injection from the perovskite active layer. Considering
that a reduction of device hysteresis is also observed by graphene
addition, the laser pyrolysis technique, which is compatible with
large-scale industrial developments, is therefore a powerful tool
for the production of efficient optoelectronic devices based on a
broad range of carbon nano-objects.
The development of indium-free transparent conductive oxides (TCOs) on polymer substrates for flexible devices requires deposition at low temperatures and a limited thermal treatment. In this paper, we investigated the optical and electrical properties of ZnO/Cu/ZnO multi-layer electrodes obtained by ion beam sputtering at room temperature for flexible optoelectronic devices. This multilayer structure has the advantage of adjusting the layer thickness to favor antireflection and surface plasmon resonance of the metallic layer. We found that the optimal electrode is made up of a 10 nm-thick Cu layer between two 40 nm-thick ZnO layers, which results in a sheet resistance of 12 omega/(see symbol), a high transmittance of 85% in the visible range, and the highest figure of merit of 5.4 x 10(-3) (see symbol)/omega. A P3HT:PCBM-based solar cell showed a power conversion efficiency (PCE) of 2.26% using the optimized ZnO (40 nm)/Cu (10 nm)/ZnO (40 nm) anode.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.