title: Carbon nanotubes as an efficient hole collector for high voltage methylammonium lead bromide perovskite solar cells.
abstract: A high open circuit voltage (V(OC)) close to 1.4 V under AM 1.5, 100 mW cm(-2) conditions is achieved when carbon nanotubes (CNTs) are used as a hole conductor in methyl ammonium lead bromide (MAPbBr3) perovskite solar cells. Time-resolved photoluminescence and impedance spectroscopy investigations suggest that the observed high V(OC) is a result of the better charge extraction and lower recombination of the CNT hole conductor. Tandem solar cells with all perovskite absorbers are demonstrated with a MAPbBr3/CNT top cell and a MAPbI3 bottom cell, achieving a V(OC) of 2.24 V in series connection. The semitransparent and high voltage MAPbBr3/CNT solar cells show great potential for applications in solar cell windows, tandem solar cells and solar driven water splitting.
authors.affiliation: Energy Research Institute @ NTU (ERI@N), Nanyang Technological University, Techno Plaza, 50 Nanyang Drive, 637553, Singapore. lydiaWong@ntu.edu.sg.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.affiliation: Energy Research Institute @ NTU (ERI@N), Nanyang Technological University, Techno Plaza, 50 Nanyang Drive, 637553, Singapore. lydiaWong@ntu.edu.sg.
authors.forename: Pablo P
authors.initials: PP
authors.lastname: Boix
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore.
authors.forename: Guichuan
authors.initials: G
authors.lastname: Xing
authors.affiliation: Energy Research Institute @ NTU (ERI@N), Nanyang Technological University, Techno Plaza, 50 Nanyang Drive, 637553, Singapore. lydiaWong@ntu.edu.sg and School of Materials Science and Engineering, Nanyang Technological University (NTU), Block N4.1, Nanyang Avenue, 639798, Singapore.
authors.forename: Kunwu
authors.initials: K
authors.lastname: Fu
authors.affiliation: Energy Research Institute @ NTU (ERI@N), Nanyang Technological University, Techno Plaza, 50 Nanyang Drive, 637553, Singapore. lydiaWong@ntu.edu.sg.
authors.forename: Sneha A
authors.initials: SA
authors.lastname: Kulkarni
authors.affiliation: Energy Research Institute @ NTU (ERI@N), Nanyang Technological University, Techno Plaza, 50 Nanyang Drive, 637553, Singapore. lydiaWong@ntu.edu.sg.
authors.forename: Sudip K
authors.initials: SK
authors.lastname: Batabyal
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Anyuan
authors.initials: A
authors.lastname: Cao
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore.
authors.forename: Tze Chien
authors.initials: TC
authors.lastname: Sum
authors.affiliation: Energy Research Institute @ NTU (ERI@N), Nanyang Technological University, Techno Plaza, 50 Nanyang Drive, 637553, Singapore. lydiaWong@ntu.edu.sg and School of Materials Science and Engineering, Nanyang Technological University (NTU), Block N4.1, Nanyang Avenue, 639798, Singapore and Singapore-Berkeley Research Initiative for Sustainable Energy, 1 Create Way, 138602, Singapore.
authors.forename: Nripan
authors.initials: N
authors.lastname: Mathews
authors.affiliation: Energy Research Institute @ NTU (ERI@N), Nanyang Technological University, Techno Plaza, 50 Nanyang Drive, 637553, Singapore. lydiaWong@ntu.edu.sg and School of Materials Science and Engineering, Nanyang Technological University (NTU), Block N4.1, Nanyang Avenue, 639798, Singapore and Singapore-Berkeley Research Initiative for Sustainable Energy, 1 Create Way, 138602, Singapore.
authors.forename: Lydia Helena
authors.initials: LH
authors.lastname: Wong