Efficient Planar Perovskite Solar Cells with Improved Fill Factor via Interface Engineering with Graphene

Abstract

Organic-inorganic hybrid lead halide perovskites have been widely investigated in optoelectronics both experimentally and theoretically. The present work incorporates chemically modified graphene into nanocrystal SnO as the electron transporting layer (ETL) for highly efficient planar perovskite solar cells. The modification of SnO with highly conductive two-dimensional naphthalene diimide-graphene can increase surface hydrophobicity and form van der Waals interaction between the surfactant and the organic-inorganic hybrid lead halide perovskite compounds. As a result, highly efficient perovskite solar cells with power conversion efficiency of 20.2% can be achieved with an improved fill factor of 82%, which could be mainly attributed to the augmented charge extraction and transport.

Chlorine‐modified SnO2 electron transport layer for high‐efficiency perovskite solar cells

“…The device performance improvement was attributed to high conductivity, high electron mobility, and low trap‐state density of the GQD:SnO 2 ETL compared to those of the SnO 2 ETL . Recently, Wang et al adopted naphthalene diimide graphene‐modified SnO 2 film as an ETL in PSCs, and a high PCE of 20.2% was achieved with a fill factor (FF) as high as 82%, which could be ascribed to enhanced electron extraction for suppressed charge accumulation at the ETL/perovskite interface, along with the increased surface hydrophobicity and interaction between the surfactant and perovskite . Very recently, Park et al prepared a SnO 2 ETL modified with 3‐(1‐pyridinio)‐1‐propanesulfonate and achieved a significant improvement in the efficiency from 19.63% for pristine SnO 2 ETL to 21.43% along with improved stability; meanwhile, the hysteresis was also reduced .…”

“…40 Recently, Wang et al adopted naphthalene diimide graphene-modified SnO 2 film as an ETL in PSCs, and a high PCE of 20.2% was achieved with a fill factor (FF) as high as 82%, which could be ascribed to enhanced electron extraction for suppressed charge accumulation at the ETL/perovskite interface, along with the increased surface hydrophobicity and interaction between the surfactant and perovskite. 39 Very recently, Park et al prepared a SnO 2 ETL modified with 3-(1-pyridinio)-1-propanesulfonate and achieved a significant improvement in the efficiency from 19.63% for pristine SnO 2 ETL to 21.43% along with improved stability; meanwhile, the hysteresis was also reduced. 44 As the electron extraction and transfer were improved, both the charge buildup and carrier recombination at the perovskite/SnO 2 interface were reduced after the modification of the SnO 2 surface with 3-(1-pyridinio)-1-propanesulfonate.…”

Stable and High‐Efficiency Methylammonium‐Free Perovskite Solar Cells

“…Nevertheless, after that, a little content of PbBr 2 had led dramatically decreased for J SC to 22.77 mA cm −2 , indicting the double‐edged sword effect of additives for PbBr 2 . Generally speaking, the fill factor (FF) of the PSCs are sensitive to the quality of the perovskite layer as well as those of the electron transport layers and the hole transport layers . As for FF in without MA PSCs, it exhibited better change from 72.96% (sample 0) to 75.10% (sample 0.05), 76.82% (sample 0.1), and 78.33% (sample 0.15).…”

High‐Mobility Hydrophobic Conjugated Polymer as Effective Interlayer for Air‐Stable Efficient Perovskite Solar Cells

“…All six photovoltaic parameters, especially FF (78.50 vs. 72.25%) are enhanced by introducing PD‐10‐DTTE‐7 as interlayer between perovskite layer and spiro‐OMeTAD. As we know that the FF of the perovskite solar cells are sensitive to the quality of the perovskite layer as well as those of the electron transport layers and the hole transport layers . When using polymer as a HTM, it intimately contacted the rough perovskite surface rather than small molecules.…”