1. Volume 2, Issue 2, Pages 296-306 (February 2018)
Control of Electrical Potential Distribution for High-Performance Perovskite Solar Cells 
Molang Cai, Nobuyuki Ishida, Xing Li, Xudong Yang, Takeshi Noda, Yongzhen Wu, Fengxian Xie, Hiroyoshi Naito, Daisuke Fujita, Liyuan Han 
Joule 
Volume 2, Issue 2, Pages (February 2018)
DOI: /j.joule
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2. Joule 2018 2, DOI: ( /j.joule )
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3. Figure 1
KPFM Characterizations of PSCs for the Mesoporous and Planar Structures
(A and B) Scanning electron microscopy images of the cross-section of the mp-TiO2 (A) and c-TiO2 (B) devices.
(C and D) Topographic image took on the cross-sectional surface of the mp-TiO2 (C) and c-TiO2 (D) devices.
(E–H) CPD maps (KPFM images) taken in the same position as the topographic image of mp-TiO2-based (E) and c-TiO2-based (F) devices in short-circuit configuration in dark conditions and of mp-TiO2-based (G) and c-TiO2-based (H) devices in open-circuit configuration under light irradiation conditions.
(I and J) Line profiles taken at the position marked by white rectangles in the KPFM images for mp-TiO2 (I) and c-TiO2 (J).
(K and L) Difference CPD profile between dark and illuminated conditions in (I) and (J) for mp-TiO2 (K) and c-TiO2 (L), respectively.
(M) Schematic of the set-up used for KPFM measurements under dark and light conditions.
c, compact; CPD, contact potential difference; FTO, fluorine-doped tin oxide; mp, mesoporous; PS, perovskite; Spiro, 2,2′,7,7′-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene; ETM, electron transport material; FTO, fluorine-doped tin oxide; HTM, hole transport material; Vdc, DC voltage; Vmod, modulation voltage.
Joule 2018 2, DOI: ( /j.joule )
Copyright © 2017 Elsevier Inc. Terms and Conditions

4. Figure 2
KPFM Characterizations of the Mesoporous Type PSCs Fabricated Using MAI- and PbI2-Rich Precursors
(A–F) Scanning electron microscopic images of the cross-section of devices based on (A) PbI2/MAI = 1.0:1.05 and (B) PbI2/MAI = 1.05:1.0 precursors. Topographic images taken on the cross-sectional surface of devices based on (C) PbI2/MAI = 1.0:1.05 and (D) PbI2/MAI = 1.05:1.0 precursors. Line profiles taken from the KPFM images obtained under dark and light irradiation conditions for devices based on (E) PbI2/MAI = 1.0:1.05 and (F) PbI2/MAI = 1.05:1.0 precursors.
(G and H) Difference CPD profile between dark and illuminated conditions in (E) and (F) for devices based on (G) PbI2/MAI = 1.0:1.05 and (H) PbI2/MAI = 1.05:1.0 precursors, respectively.
(I) Schematic of charge separation in mesoporous structure PSCs. ETM, electron transport material; HTM, hole transport material.
Joule 2018 2, DOI: ( /j.joule )
Copyright © 2017 Elsevier Inc. Terms and Conditions

5. Figure 3
KPFM Characterizations of the Planar Type PSCs Fabricated Using MAI- and PbI2-Rich Precursors
(A–F) Scanning electron microscopic images of the cross-section of the device based on (A) PbI2/MAI = 1.0:1.05 and (B) PbI2/MAI = 1.05:1.0 precursors. Topographic images taken on the cross-sectional surface of the device based on (C) PbI2/MAI = 1.0:1.05 and (D) PbI2/MAI = 1.05:1.0 precursors. Line profiles taken from the KPFM images obtained under dark and light irradiation conditions based on (E) PbI2/MAI = 1.0:1.05 and (F) PbI2/MAI = 1.05:1.0 precursors.
(G and H) Difference CPD profile between dark and illuminated conditions in (E) and (F) based on (G) PbI2/MAI = 1.0:1.05 and (H) PbI2/MAI = 1.05:1.0 precursors, respectively.
(I and J) Schematic of charge separation in the planar structure PSCs for (I) MAI-rich and (J) PbI2-rich precursors.
Joule 2018 2, DOI: ( /j.joule )
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6. Figure 4
Comparison of the Photovoltaic Performances of Mesoporous and Planar PSCs
(A and B) Dependence of (A) reverse bias saturation current and (B) ideality factor of planar and mesoporous PSCs on PbI2/CH3NH3I (MAI) mole ratio.
(C and D) Dependence of (C) open voltage (Voc) and (D) cell efficiency on PbI2/MAI mole ratio for mesoporous and planar PSCs. The SDs by statistics of ten devices were measured on cell performance to evaluate reproducibility.
Joule 2018 2, DOI: ( /j.joule )
Copyright © 2017 Elsevier Inc. Terms and Conditions