title: Graphene-Perovskite Solar Cells Exceed 18 % Efficiency: A Stability Study.
abstract: Interface engineering is performed by the addition of graphene and related 2 D materials (GRMs) into perovskite solar cells (PSCs), leading to improvements in the power conversion efficiency (PCE). By doping the mesoporous TiO2layer with graphene flakes (mTiO2+G), produced by liquid-phase exfoliation of pristine graphite, and by inserting graphene oxide (GO) as an interlayer between the perovskite and hole-transport layers, using a two-step deposition procedure in air, we achieved a PCE of 18.2 %. The obtained PCE value mainly results from improved charge-carrier injection/collection with respect to conventional PSCs. Although the addition of GRMs does not influence the shelf life, it is beneficial for the stability of PSCs under several aging conditions. In particular, mTiO2+G PSCs retain more than 88 % of the initial PCE after 16 h of prolonged 1 sun illumination at the maximum power point. Moreover, when subjected to prolonged heating at 60 °C, the GO-based structures show enhanced stability with respect to mTiO2+G PSCs, as a result of thermally induced modification at the mTiO2+G/perovskite interface. The exploitation of GRMs in the form of dispersions and inks opens the way for scalable large-area production, advancing the possible commercialization of PSCs.
authors.affiliation: C.H.O.S.E. (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome Tor Vergata, via del Politecnico 1, 00133, Rome, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Agresti
authors.affiliation: C.H.O.S.E. (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome Tor Vergata, via del Politecnico 1, 00133, Rome, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Pescetelli
authors.affiliation: C.H.O.S.E. (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome Tor Vergata, via del Politecnico 1, 00133, Rome, Italy.
authors.forename: Babak
authors.initials: B
authors.lastname: Taheri
authors.affiliation: Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, 16163, Genova, Italy.
authors.forename: Antonio Esaù
authors.initials: AE
authors.lastname: Del Rio Castillo
authors.affiliation: C.H.O.S.E. (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome Tor Vergata, via del Politecnico 1, 00133, Rome, Italy.
authors.forename: Lucio
authors.initials: L
authors.lastname: Cinà
authors.affiliation: Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, 16163, Genova, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Bonaccorso
authors.affiliation: C.H.O.S.E. (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome Tor Vergata, via del Politecnico 1, 00133, Rome, Italy. aldo.dicarlo@uniroma2.it.
authors.forename: Aldo
authors.initials: A
authors.lastname: Di Carlo
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry*; D004355:Drug Stability; D011211:Electric Power Supplies; D006108:Graphite / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D010087:Oxides / Q000737:chemistry*; D012993:Solar Energy; D013696:Temperature; D014025:Titanium / Q000737:chemistry*
chemical_list: D017610:Calcium Compounds; D010087:Oxides; C059910:perovskite; C009495:titanium dioxide; D006108:Graphite; D014025:Titanium
keywords: energy conversion; graphene; perovskite; solar cells; stability