title: A layered hybrid perovskite solar-cell absorber with enhanced moisture stability.
abstract: Two-dimensional hybrid perovskites are used as absorbers in solar cells. Our first-generation devices containing (PEA)2(MA)2[Pb3I10] (1; PEA=C6H5(CH2)2NH3(+), MA=CH3NH3(+)) show an open-circuit voltage of 1.18 V and a power conversion efficiency of 4.73%. The layered structure allows for high-quality films to be deposited through spin coating and high-temperature annealing is not required for device fabrication. The 3D perovskite (MA)[PbI3] (2) has recently been identified as a promising absorber for solar cells. However, its instability to moisture requires anhydrous processing and operating conditions. Films of 1 are more moisture resistant than films of 2 and devices containing 1 can be fabricated under ambient humidity levels. The larger bandgap of the 2D structure is also suitable as the higher bandgap absorber in a dual-absorber tandem device. Compared to 2, the layered perovskite structure may offer greater tunability at the molecular level for material optimization.
authors.affiliation: Department of Chemistry, Stanford University, Stanford, CA 94305 (USA).
authors.forename: Ian C
authors.initials: IC
authors.lastname: Smith
authors.forename: Eric T
authors.initials: ET
authors.lastname: Hoke
authors.forename: Diego
authors.initials: D
authors.lastname: Solis-Ibarra
authors.forename: Michael D
authors.initials: MD
authors.lastname: McGehee
authors.forename: Hemamala I
authors.initials: HI
authors.lastname: Karunadasa
keywords: layered compounds; materials science; perovskite; photovoltaics; solar cells