title: Hydrophobic Organic Hole Transporters for Improved Moisture Resistance in Metal Halide Perovskite Solar Cells.
abstract: Solar cells based on organic-inorganic perovskite semiconductor materials have recently made rapid improvements in performance, with the best cells performing at over 20% efficiency. With such rapid progress, questions such as cost and solar cell stability are becoming increasingly important to address if this new technology is to reach commercial deployment. The moisture sensitivity of commonly used organic-inorganic metal halide perovskites has especially raised concerns. Here, we demonstrate that the hygroscopic lithium salt commonly used as a dopant for the hole transport material in perovskite solar cells makes the top layer of the devices hydrophilic and causes the solar cells to rapidly degrade in the presence of moisture. By using novel, low cost, and hydrophobic hole transporters in conjunction with a doping method incorporating a preoxidized salt of the respective hole transporters, we are able to prepare efficient perovskite solar cells with greatly enhanced water resistance.
authors: University of Oxford , Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom.|Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
authors: Tomas
authors: T
authors: Leijtens
authors: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
authors: Tommaso
authors: T
authors: Giovenzana
authors: University of Oxford , Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom.
authors: Severin N
authors: SN
authors: Habisreutinger
authors: Department of Chemistry and Geochemistry, Colorado School of Mines , 156 Coolbaugh Hall, 1012 14th Street, Golden, Colorado 80401, United States.
authors: Jonathan S
authors: JS
authors: Tinkham
authors: University of Oxford , Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom.
authors: Nakita K
authors: NK
authors: Noel
authors: Oxford Photovoltaics Ltd , Centre for Innovation and Enterprise, Begbroke Science Park, Woodstock Road, Oxford, OX5 1PF, United Kingdom.
authors: Brett A
authors: BA
authors: Kamino
authors: University of Oxford , Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom.
authors: Golnaz
authors: G
authors: Sadoughi
authors: Department of Chemistry and Geochemistry, Colorado School of Mines , 156 Coolbaugh Hall, 1012 14th Street, Golden, Colorado 80401, United States.
authors: Alan
authors: A
authors: Sellinger
authors: University of Oxford , Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom.
authors: Henry J
authors: HJ
authors: Snaith
keywords: doping; hole transporters; humidity; hydrophobic; perovskite solar cells; stability