title: Improved Open- Circuit Voltage in ZnO-PbSe Quantum Dot Solar Cells by Understanding and Reducing Losses Arising from the ZnO Conduction Band Tail.
abstract: Colloidal quantum dot solar cells (CQDSCs) are attracting growing attention owing to significant improvements in efficiency. However, even the best depleted-heterojunction CQDSCs currently display open-circuit voltages (VOCs) at least 0.5 V below the voltage corresponding to the bandgap. We find that the tail of states in the conduction band of the metal oxide layer can limit the achievable device efficiency. By continuously tuning the zinc oxide conduction band position via magnesium doping, we probe this critical loss pathway in ZnO-PbSe CQDSCs and optimize the energetic position of the tail of states, thereby increasing both theVOC(from 408 mV to 608 mV) and the device efficiency.
authors.affiliation: Department of Materials Science and Metallurgy, 27 Charles Babbage Road, University of Cambridge Cambridge, CB3 0FS, UK.
authors.forename: Robert L Z
authors.initials: RL
authors.lastname: Hoye
authors.affiliation: Department of Physics, JJ Thomson Avenue, University of Cambridge Cambridge, CB3 0HE, UK.
authors.forename: Bruno
authors.initials: B
authors.lastname: Ehrler
authors.affiliation: Department of Physics, JJ Thomson Avenue, University of Cambridge Cambridge, CB3 0HE, UK.
authors.forename: Marcus L
authors.initials: ML
authors.lastname: Böhm
authors.affiliation: Department of Materials Science and Metallurgy, 27 Charles Babbage Road, University of Cambridge Cambridge, CB3 0FS, UK ; Instituto de Ciencia de Materiales de Barcelona, ICMAB-CSIC, Campus de la UAB Bellaterra, 08193, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Muñoz-Rojas
authors.affiliation: Petrochemicals Research Institute, King Abdulaziz City for Science and Technology Riyadh, 11442, Kingdom of Saudi Arabia.
authors.forename: Rashid M
authors.initials: RM
authors.lastname: Altamimi
authors.affiliation: National Nanotechnology Research Centre, King Abdulaziz City for Science and Technology Riyadh, 11442, Kingdom of Saudi Arabia.
authors.forename: Ahmed Y
authors.initials: AY
authors.lastname: Alyamani
authors.affiliation: Department of Physics, JJ Thomson Avenue, University of Cambridge Cambridge, CB3 0HE, UK.
authors.forename: Yana
authors.initials: Y
authors.lastname: Vaynzof
authors.affiliation: Department of Physics, JJ Thomson Avenue, University of Cambridge Cambridge, CB3 0HE, UK.
authors.forename: Aditya
authors.initials: A
authors.lastname: Sadhanala
authors.affiliation: Department of Materials Science and Metallurgy, 27 Charles Babbage Road, University of Cambridge Cambridge, CB3 0FS, UK.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Ercolano
authors.affiliation: Department of Physics, JJ Thomson Avenue, University of Cambridge Cambridge, CB3 0HE, UK.
authors.forename: Neil C
authors.initials: NC
authors.lastname: Greenham
authors.affiliation: Department of Physics, JJ Thomson Avenue, University of Cambridge Cambridge, CB3 0HE, UK.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Friend
authors.affiliation: Department of Materials Science and Metallurgy, 27 Charles Babbage Road, University of Cambridge Cambridge, CB3 0FS, UK.
authors.forename: Judith L
authors.initials: JL
authors.lastname: MacManus-Driscoll
authors.affiliation: Department of Materials Science and Metallurgy, 27 Charles Babbage Road, University of Cambridge Cambridge, CB3 0FS, UK ; Department of Physics, JJ Thomson Avenue, University of Cambridge Cambridge, CB3 0HE, UK.
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Musselman