Electrochromic Metallo-Organic Nanoscale Films: Fabrication, Color Range, and Devices Neta Elool Dov, 1 Sreejith Shankar, 1 Dana Cohen, 1 Tatyana Bendikov, 2 Katya Rechav, 2 Linda J. W. Shimon, 2 Michal Lahav, 1* and Milko E. van der Boom 1* 1 Department of Organic Chemistry, 2 Department of Chemical Research Support, Weizmann Institute of Science, 7610001 Rehovot, Israel. Email: michal.lahav@weizmann.ac.il; milko.vanderboom@weizmann.ac.il
Figure S1. Unit cell of a single crystal of complex 1 (space group P-1) in ORTEP representation with thermal ellipsoids set at the 50% probability level. Hydrogen atoms and the PF6 - anions are omitted for clarity. Color code: white, carbon; blue, nitrogen; yellow, iron. The asymmetric unit comprises of 1-fac-Λ, and one 1-fac-Λ/1-mer-Λ mixed site. S1
Figure S2. Characterization of [MA1 FTO/glass 10 Ω/ ] after 18 deposition cycles. (A) Photographs of an FTO/glass substrate coated with MA1 showing large area processability. (B) Representative optical microscopy image. (C) Chronoamperometry; substrate dimensions: 2 cm 2 cm. (D) CVs at scan rates of 0.01-1.0 V/s. The arrows indicate the increase of the current with increasing scan rate. Substrate dimensions: 2 cm 2 cm, electrolyte solution: 0.1 M TBAPF6/ACN. (E) SEC measurements at different switching times. Substrate dimensions: 2 cm 2 cm. (F) Photographs of MA1 (4 cm 4 cm) in the reduced (colored) and oxidized (bleached) states. (C,E,F): A potential window of 0.4-1.6 V and 0.1 M TBAPF6/ACN electrolyte solution. (G) Photographs of a solid state device (6 cm 6 cm) in the reduced (colored) and oxidized (bleached) states. A potential window of -2V to 3V was used. The device consists of two FTO/glass electrodes and a PMMA-based electrolyte gel. S2
Table S1. RGB values for the molecular assemblies (MAs) based on Photoshop analysis. Each MA was sampled at ten different points to obtain average RGB values and its standard deviations. S3
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Figure S3. Characterization of [MA1 ITO/PET 30 Ω/ ] (A) Ex-situ absorption spectra at different deposition cycles of complex 1 and PdCl2(PhCN)2. The baseline (black) corresponds to the absorbance of bare ITO/PET. Inset: Intensities of the absorbance of the MLCT band at λmax = 573 nm plotted against the number of deposition cycles showing a linear growth behavior. (B) Normalized X-ray photoelectron spectra showing the Fe 2+ 2p, N 1s and Pd 2+ 3d bands. In Fe 2p region Fe signal is shown with (violet line) and without (gray line) subtraction of F 1s satellite background signal (assigned by ). (C) CV at a scan rate of 0.1 V/s, substrate dimensions: 1 cm 1.5 cm. (D) SEM image showing the cross-section of a film that was milled by 30 kev Ga + focused ion beam (FIB). Pt coating was used to prevent ion beam damage. (E) Chronoamperometry using a potential window of 0.4-1.6 V and at a pulse width of 20 s. Substrate dimensions: 1 cm 5 cm. (F) Photograph of an ITO/PET substrate (6 cm 6 cm) coated with MA1. (G) CVs at scan rates of 0.01V - 0.9 V/s. The arrows indicate the increase of the current with increasing of the scan rate. Substrate dimension: 2 cm 2 cm. (H) Exponential and linear correlations between peak current and scan rate (left) or peak current and the square root of scan rate (right), respectively, during oxidation (top) and reduction (bottom). (R 2 > 0.99 for all fits). (I) SEC measurements using a potential window of 0.4V to 1.6V at different switching times, substrate dimensions: 2 cm 2 cm. 0.1 M TBAPF6/ACN was used as the supporting electrolyte in C, E and G-I. (J) Correlation between the contrast ratio and the switching time. The contrast ratio was calculated based on the transmittance values presented in Figure S3I. (B)-(J) Data shown for MA1 after 18 deposition cycles. S5
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Figure S4. Characterization of [MA2 FTO/glass 10 Ω/ ]. (A) Ex-situ absorption spectra at different deposition cycles of complex 2 and PdCl2(PhCN)2. The baseline (black) corresponds to the absorbance of bare FTO/glass. Inset: intensities of the absorbance of the MLCT band at λmax = 598 nm plotted against the number of deposition cycles showing a linear growth behavior. (B) Normalized X-ray photoelectron spectra showing the Fe 2+ 2p, N 1s and Pd 2+ 3d bands. In Fe 2p region, the signal is shown with (violet line) and without (gray line) subtraction of F 1s satellite background signal (assigned by ). (C) CV at a scan rate of 0.1 V/s. (D) SEM image showing the cross-section of a film that was milled by 30 kev Ga + focused ion beam (FIB). Pt coating was used to prevent ion beam damage. (E) Chronoamperometry using a potential window of 0.4 V - 1.8 V and at a pulse width of 3 s. Substrate dimensions: 1 cm 2 cm. (F) Photograph of an FTO/glass substrate (2 cm 2 cm) coated with MA2. (G) CVs at scan rates of 0.01-0.7 V/s. The arrows indicate the increase of the current with increasing of the scan rate. (H) Exponential and linear correlations between peak current and scan rate (left) or peak current and the square root of scan rate (right), respectively, in the oxidative (top) and reductive (bottom) directions (R 2 > 0.99 for all fits). (I) SEC measurements using a potential window of 0.4V to 1.8 V at different switching times. 0.1 M TBAPF6/ACN was used as the supporting electrolyte in C, E, and G-I and the substrate dimension (C, F-I) was 2 cm 2 cm. (B)-(I) Data shown for MA2 after 18 deposition cycles. S7
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Figure S5. Characterization of [MA1 2 FTO/glass 10 Ω/ ]. (A) Ex-situ optical absorption spectra at different deposition cycles of a mixture of complexes 1 / 2, and of PdCl2(PhCN)2. The baseline (black) corresponds to the absorbance of a bare FTO/glass substrate. Inset: Intensities of the absorbance of the MLCT band at λmax = 589 nm plotted against the number of deposition steps showing a linear growth behavior. (B) Normalized X-ray photoelectron spectra showing the Fe 2+ 2p, N 1s and Pd 2+ 3d bands. In Fe 2p region Fe signal is shown with (violet line) and without (gray line) subtraction of F 1s satellite background signal (assigned by ). (C) CV at a scan rate of 0.1 V/s. (D) SEM image showing the cross-section of a film that was milled by 30 kev Ga + focused ion beam (FIB). Pt coating was used to prevent ion beam damage. (E) Chronoamperometry using a potential window of 0.6 V - 2 V and at a pulse width of 5 s. (F) Photograph of an FTO/glass substrate coated with MA1 2. (G) CVs at scan rates of 0.01-1.0 V/s. The arrows indicate the increase of the current with increasing of the scan rate. (H) Exponential and linear correlations between peak current and scan rate (left) or peak current and the square root of scan rate (right), respectively, in oxidative (top) and reductive (bottom) directions (R 2 > 0.99 for all fits). (I) SEC measurements using a potential window of 0.6-2.0 V at different switching times. 0.1 M TBAPF6/ACN was used as the supporting electrolyte in C, E, and G-I and the substrate dimension (C, E, F-I) was 2 cm 2 cm. (B)-(I) Data shown for MA1 2 after 18 deposition cycles. S9
Figure S6. Characterizations of [MA1 2 FTO/glass 10 Ω/ ] vs deposition cycles. (A) Coloration efficiency as a function of the number of deposition cycles. (B) Left: CVs after 1, 5, 10, 15 and 18 deposition cycles. Right: anodic (blue squares) and cathodic (red circles) currents as a function of the number of deposition cycle. (C) Chronocoulometry after 1, 5, 10, 15 and 18 deposition cycles. (D) Charge as a function of the number of deposition cycle. All electrochemical measurements (A-D) were performed at a potential window of 0.6 V to 2 V, on 2 cm 2 cm assemblies, using 0.1 M TBAPF6/ACN electrolyte solution. S10
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Figure S7. Characterization of [MA1 2 ITO/PET 30 Ω/ ]. (A) Ex-situ optical absorption spectra at different deposition cycles of complexes 1 / 2, and of PdCl2(PhCN)2. The baseline (black) corresponds to the absorbance of bare ITO/PET. Inset: Intensities of the absorbance of the MLCT band at λmax = 589 nm plotted against the number of deposition cycles showing a linear growth behavior. (B) Normalized X-ray photoelectron spectra showing the Fe 2+ 2p, N 1s and Pd 2+ 3d bands. In Fe 2p region Fe signal is shown with (violet line) and without (gray line) subtraction of F 1s satellite background signal (assigned by ). (C) CV at a scan rate of 0.1 V/s. (D) SEM image showing the crosssection of a film that was milled by 30 kev Ga + focused ion beam (FIB). Pt coating was used to prevent ion beam damage. (E) Chronoamperometry using a potential window of 0.4 V - 1.8 V at a pulse width of 5 s. (F) Photograph of an ITO/PET substrate (6 cm 6 cm) coated with MA1 2. (G) CVs at scan rates of 0.025-1.0 V/s. The arrows indicate the growth direction. (H) Exponential and linear correlations between peak current and scan rate (left) or peak current and the square root of scan rate (right), respectively, in oxidative (top) and reductive (bottom) directions (R 2 > 0.99 for all fits). (I) SEC measurements using a potential window of 0.4 V to 1.8 V at different switching times. (J) Exponential correlation of the contrast ratio and the switching time. The contrast ratio was calculated based on the transmittance values presented in Figure S7I. 0.1M TBAPF6/ACN was used as the supporting electrolyte and the substrate dimension was 1 cm 5 cm in C, E, and G- J. (K) Absorption spectra corresponding to the oxidation and reduction of MA1 2. Bare ITO/PET was used for baseline (black). (B)-(K) Data shown for MA1 2 after 18 deposition cycles. S12
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Figure S8. Characterization of [MA3 FTO/glass 10 Ω/ ]. (A) Ex-situ optical absorption spectra at different deposition cycles of complex 3 and PdCl2(PhCN)2. The baseline (black) corresponds to the absorbance of bare FTO/glass. Inset: Intensities of the absorbance of the MLCT band at λmax = 495 nm plotted against the number of deposition cycles showing a linear growth behavior. (B) Normalized X-ray photoelectron spectra showing the N 1s, Pd 2+ 3d and Ru 2+ 3d bands. Ru 3d and C 1s bands are partly overlapped. (C) CV at a scan rate of 0.1 V/s. (D) SEM image showing the cross section of a film that was milled by 30 kev Ga + focused ion beam (FIB). Pt coating was used to prevent ion beam damage. (E) Chronoamperometry using a potential window of 0.8 V - 1.6 V at a pulse width of 3s. (F) Photograph of an ITO/PET substrate (4 cm 4 cm) coated with MA3. (G) CVs at scan rates 0.01-0.6 V/s. The arrows indicate the direction of growth. (H) Correlations between peak current and scan rate (left) or peak current and the square root of scan rate (right), respectively, in oxidative (top) and reductive (bottom) directions. (I) SEC measurements using a potential window of 0.8-1.6 V at different switching times. 0.1 M TBAPF6/ACN was used as the supporting electrolyte in C, E, and G-I and the substrate dimension was 2 cm 2 cm. (B)-(I) Data shown for MA3 after 12 deposition cycles. S14
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Figure S9. Characterization of [MA1 3 FTO/glass 10 Ω/ ]. (A) Ex-situ optical absorption spectra at different deposition cycles of complexes 1 / 3, and of PdCl2(PhCN)2. The baseline (black) corresponds to the absorbance of bare FTO/glass. Inset: intensities of the absorbance of the MLCT bands of complex 1 at λmax = 573 nm (purple trace) and of complex 3 at λmax = 495 nm (orange trace) plotted against the number of deposition cycles showing a linear growth behavior. (B) Normalized X-ray photoelectron spectra showing the Fe 2+ 2p, N 1s, Pd 2+ 3d and Ru 2+ 3d bands. In Fe 2p region Fe signal is shown with (violet line) and without (gray line) subtraction of F 1s satellite background signal (assigned by ). Ru 3d and C 1s bands are partly overlap. (C) CV at a scan rate of 0.1 V/s. (D) SEM image showing the cross section of a film that was milled by 30 kev Ga + focused ion beam (FIB). Pt coating was used to prevent ion beam damage. (E) Chronoamperometry using a potential window of 0.3V - 2.0 V at a pulse width of 3 s. (F) Photograph of an FTO/glass substrate coated with MA1 3. (G) CVs at scan rates of 0.01-1.0 V/s. The arrows indicate the direction of growth. (H) Exponential and linear correlations between peak current and scan rate (left) or peak current and the square root of scan rate (right), respectively, in the oxidative (top) and reductive (bottom) directions. (R 2 > 0.98 for all fits). (I) SEC measurements at different switching times using a potential window of 0.3-2.0 V. Top: max = 573 nm, bottom row: max = 495 nm. 0.1M TBAPF6/ACN was used as the supporting electrolyte in C, E, and G-I and the substrate dimension was 2 cm 2 cm. (B)-(I) Data shown for MA1 3 after 12 deposition cycles. S16
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Figure S10. Characterization of [MA4 FTO/glass 10 Ω/ ]. (A) Ex-situ optical absorption spectra at different deposition cycles of complex 4 and of PdCl2(PhCN)2. The baseline (black) corresponds to the absorbance of bare FTO/glass. Inset: intensities of the absorbance of the MLCT band at λmax = 510 nm plotted against the number of deposition cycles showing a linear growth behavior. (B) Normalized X-ray photoelectron spectra (XPS) showing the Os 2+ 4f, N 1s and Pd 2+ 3d bands. The asterisk ( * ) in the Os 4f spectra indicates the contribution of the Pd 4p overlapping band. (C) CV at a scan rate of 0.1 V/s. (D) SEM image showing the cross section of a film that was milled by 30 kev Ga + focused ion beam (FIB). Pt coating was used to prevent ion beam damage. (E) Chronoamperometry using a potential window of 0.2 V -1.4 V at a pulse width of 2 s. (F) Photograph of an FTO/glass substrate coated with MA4. (G) CVs at scan rates of 0.025-1.0 V/s. The arrows indicate the direction of growth. (H) Exponential and linear correlations between peak current and scan rate (left) or peak current and the square root of scan rate (right), respectively, in the oxidative (top) and reductive (bottom) directions (R 2 > 0.999 for all fits). (I) SEC measurements using a potential window of 0.2 V 1.4 V at different switching times. 0.1 M TBAPF6/ACN was used as the supporting electrolyte in C, E, and G-I and the substrate dimension (C, E-I) was 2 cm 2 cm. (B)-(I) Data shown for MA4 after 18 deposition cycles.. S18