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Title: Interfacial electronic structure at the CH{sub 3}NH{sub 3}PbI{sub 3}/MoO{sub x} interface

Abstract

Interfacial electronic properties of the CH{sub 3}NH{sub 3}PbI{sub 3} (MAPbI{sub 3})/MoO{sub x} interface are investigated using ultraviolet photoemission spectroscopy and X-ray photoemission spectroscopy. It is found that the pristine MAPbI{sub 3} film coated onto the substrate of poly (3,4-ethylenedioxythiophene) poly(styrenesulfonate)/indium tin oxide by two-step method behaves as an n-type semiconductor, with a band gap of ∼1.7 eV and a valence band edge of 1.40 eV below the Fermi energy (E{sub F}). With the MoO{sub x} deposition of 64 Å upon MAPbI{sub 3}, the energy levels of MAPbI{sub 3} shift toward higher binding energy by 0.25 eV due to electron transfer from MAPbI{sub 3} to MoO{sub x}. Its conduction band edge is observed to almost pin to the E{sub F}, indicating a significant enhancement of conductivity. Meanwhile, the energy levels of MoO{sub x} shift toward lower binding energy by ∼0.30 eV, and an interface dipole of 2.13 eV is observed at the interface of MAPbI{sub 3}/MoO{sub x}. Most importantly, the chemical reaction taking place at this interface results in unfavorable interface energy level alignment for hole extraction. A potential barrier of ∼1.36 eV observed for hole transport will impede the hole extraction from MAPbI{sub 3} to MoO{sub x}. On the other hand, a potential barrier of ∼0.14 eV formore » electron extraction is too small to efficiently suppress electrons extracted from MAPbI{sub 3} to MoO{sub x}. Therefore, such an interface is not an ideal choice for hole extraction in organic photovoltaic devices.« less

Authors:
; ; ; ; ; ;  [1]; ; ;  [2];  [3]
  1. Institute of Super-Microstructure and Ultrafast Process in Advanced Materials, College of Physics and Electronics, Central South University, Changsha 410083 (China)
  2. Department of Mechanical and Materials Engineering and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0656 (United States)
  3. Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States)
Publication Date:
OSTI Identifier:
22399068
Resource Type:
Journal Article
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 106; Journal Issue: 19; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0003-6951
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BINDING ENERGY; DEPOSITION; ELECTRON TRANSFER; ELECTRONIC STRUCTURE; ELECTRONS; EMISSION SPECTROSCOPY; ENERGY LEVELS; FILMS; HOLES; INTERFACES; N-TYPE CONDUCTORS; PHOTOELECTRON SPECTROSCOPY; PHOTOVOLTAIC EFFECT; POTENTIALS; SUBSTRATES; TIN OXIDES; ULTRAVIOLET RADIATION; VALENCE; X-RAY SPECTROSCOPY

Citation Formats

Liu, Peng, Liu, Xiaoliang, E-mail: xl-liu@csu.edu.cn, E-mail: ygao@pas.rochester.edu, Lyu, Lu, Xie, Haipeng, Zhang, Hong, Niu, Dongmei, Huang, Han, Bi, Cheng, Xiao, Zhengguo, Huang, Jinsong, and Gao, Yongli, E-mail: xl-liu@csu.edu.cn, E-mail: ygao@pas.rochester.edu. Interfacial electronic structure at the CH{sub 3}NH{sub 3}PbI{sub 3}/MoO{sub x} interface. United States: N. p., 2015. Web. doi:10.1063/1.4921339.
Liu, Peng, Liu, Xiaoliang, E-mail: xl-liu@csu.edu.cn, E-mail: ygao@pas.rochester.edu, Lyu, Lu, Xie, Haipeng, Zhang, Hong, Niu, Dongmei, Huang, Han, Bi, Cheng, Xiao, Zhengguo, Huang, Jinsong, & Gao, Yongli, E-mail: xl-liu@csu.edu.cn, E-mail: ygao@pas.rochester.edu. Interfacial electronic structure at the CH{sub 3}NH{sub 3}PbI{sub 3}/MoO{sub x} interface. United States. doi:10.1063/1.4921339.
Liu, Peng, Liu, Xiaoliang, E-mail: xl-liu@csu.edu.cn, E-mail: ygao@pas.rochester.edu, Lyu, Lu, Xie, Haipeng, Zhang, Hong, Niu, Dongmei, Huang, Han, Bi, Cheng, Xiao, Zhengguo, Huang, Jinsong, and Gao, Yongli, E-mail: xl-liu@csu.edu.cn, E-mail: ygao@pas.rochester.edu. Mon . "Interfacial electronic structure at the CH{sub 3}NH{sub 3}PbI{sub 3}/MoO{sub x} interface". United States. doi:10.1063/1.4921339.
@article{osti_22399068,
title = {Interfacial electronic structure at the CH{sub 3}NH{sub 3}PbI{sub 3}/MoO{sub x} interface},
author = {Liu, Peng and Liu, Xiaoliang, E-mail: xl-liu@csu.edu.cn, E-mail: ygao@pas.rochester.edu and Lyu, Lu and Xie, Haipeng and Zhang, Hong and Niu, Dongmei and Huang, Han and Bi, Cheng and Xiao, Zhengguo and Huang, Jinsong and Gao, Yongli, E-mail: xl-liu@csu.edu.cn, E-mail: ygao@pas.rochester.edu},
abstractNote = {Interfacial electronic properties of the CH{sub 3}NH{sub 3}PbI{sub 3} (MAPbI{sub 3})/MoO{sub x} interface are investigated using ultraviolet photoemission spectroscopy and X-ray photoemission spectroscopy. It is found that the pristine MAPbI{sub 3} film coated onto the substrate of poly (3,4-ethylenedioxythiophene) poly(styrenesulfonate)/indium tin oxide by two-step method behaves as an n-type semiconductor, with a band gap of ∼1.7 eV and a valence band edge of 1.40 eV below the Fermi energy (E{sub F}). With the MoO{sub x} deposition of 64 Å upon MAPbI{sub 3}, the energy levels of MAPbI{sub 3} shift toward higher binding energy by 0.25 eV due to electron transfer from MAPbI{sub 3} to MoO{sub x}. Its conduction band edge is observed to almost pin to the E{sub F}, indicating a significant enhancement of conductivity. Meanwhile, the energy levels of MoO{sub x} shift toward lower binding energy by ∼0.30 eV, and an interface dipole of 2.13 eV is observed at the interface of MAPbI{sub 3}/MoO{sub x}. Most importantly, the chemical reaction taking place at this interface results in unfavorable interface energy level alignment for hole extraction. A potential barrier of ∼1.36 eV observed for hole transport will impede the hole extraction from MAPbI{sub 3} to MoO{sub x}. On the other hand, a potential barrier of ∼0.14 eV for electron extraction is too small to efficiently suppress electrons extracted from MAPbI{sub 3} to MoO{sub x}. Therefore, such an interface is not an ideal choice for hole extraction in organic photovoltaic devices.},
doi = {10.1063/1.4921339},
journal = {Applied Physics Letters},
issn = {0003-6951},
number = 19,
volume = 106,
place = {United States},
year = {2015},
month = {5}
}