Zr Incorporation into TiO2 Electrodes Reduces Hysteresis and Improves Performance in Hybrid Perovskite Solar Cells while Increasing Carrier Lifetimes.
We investigate zirconium (Zr) incorporation into the titanium dioxide (TiO2) electron-transporting layer used in organometal halide perovskite photovoltaics. Compared to Zr-free controls, solar cells employing electrodes containing Zr exhibit increased power conversion efficiency (PCE) and decreased hysteresis. We use transient photovoltage and photocurrent extraction to measure carrier lifetimes and densities and observe longer carrier lifetimes and higher charge densities in devices on Zr-containing electrodes at microsecond times as well as longer persistent photovoltages extending from ∼milliseconds to tens of seconds. We characterize the surface stoichiometry and change in work function and reduction potential of the TiO2 upon incorporation of Zr and discuss the charge recombination at the TiO2 interface in the context of these variables. Finally, we show that the combination of Zr-TiO2 electrode modification with device pyridine treatment leads to a cumulative improvement in performance.
Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Hirokazu
H
Nagaoka
Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Fei
F
Ma
Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Dane W
DW
deQuilettes
Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Sarah M
SM
Vorpahl
Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Micah S
MS
Glaz
Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Adam E
AE
Colbert
Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
Mark E
ME
Ziffer
Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States.
David S
DS
Ginger
D017610:Calcium Compounds / Q000737:chemistry*; D004566:Electrodes; D010087:Oxides / Q000737:chemistry*; D012993:Solar Energy; D014025:Titanium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
D017610:Calcium Compounds; D010087:Oxides; C059910:perovskite; C009495:titanium dioxide; D015040:Zirconium; D014025:Titanium
organometal halide; photovoltage; pyridine; surface passivation; titania; zirconium