Ion Trapping and De-trapping in Amorphous Tungsten Oxide Thin ...
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Ion Trapping and De-trapping in Amorphous Tungsten Oxide Thin Films Observed by Real-time Electro-optical Monitoring
Rui-Tao Wen,a,* Miguel A. Arvizu,a Michael Morales-Luna,a Claes G. Granqvista and Gunnar A. Niklassona a
Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, P. O.
Box 534, SE-75121 Uppsala, Sweden *Corresponding author. Email: [email protected]; present address: Materials Processing Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States. Keywords: WO3, thin films, electrochromism, ion traps, de-trapping
Figure S1. Cyclic voltammogram for a ~300-nm-thick amorphous WO3 film, recorded at a scan rate of 0.1 mV s–1 (~11 h for one cycle).
Figure S2. X-ray diffractograms for a ~300-nm-thick WO3 thin film subjected to the shown treatments. Intercalation and de-intercalation of Li ions took place at 0.1 mV s–1. Intensities are shown in arbitrary units (a.u.) and curves are vertically displaced. Dashed red lines mark peak positions originating from the ITO coated onto the glass substrate. No distinct diffraction features can be assigned to WO3 which hence is amorphous irrespectively of treatment.
Figure S3. Current density vs. time during potentiostatic de-trapping at the shown potential, and for the shown time periods, of a ~300-nm-thick WO3 film.
Figure S4. (a) Charge capacity of a ~300-nm-thick WO3 film after the following electrochemical operations: (I) 10 cyclic voltammetry (CV) cycles were run in the range of 2.0–4.0 V vs. Li/Li+ with a scan rate of 20 mV s–1 followed by a resting period of 10 minutes, then (II) 20 CV cycles were run in the range of 1.5–4.0 V vs. Li/Li+ with a scan rate of 10 mV s–1 followed by galvanostatic de-trapping at a current density of ~3.0 μA cm–2 for 2 h, and finally (III) another 10 CV cycles were run as in (I) followed by de-trapping as before. (b) In situ optical transmittance at a wavelength of 550 nm recorded concurrently with the measurements in (a); inset is a close-up view of transmittance modulation during (III). Note that the horizontal axes differ in (a) and (b).
Ion Trapping and De-trapping in Amorphous Tungsten Oxide Thin Films Observed by Real-time Electro-optical Monitoring
Rui-Tao Wen,a,* Miguel A. Arvizu,a Michael Morales-Luna,a Claes G. Granqvista and Gunnar A. Niklassona a
Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, P. O.
Box 534, SE-75121 Uppsala, Sweden *Corresponding author. Email: [email protected]; present address: Materials Processing Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States. Keywords: WO3, thin films, electrochromism, ion traps, de-trapping
Figure S1. Cyclic voltammogram for a ~300-nm-thick amorphous WO3 film, recorded at a scan rate of 0.1 mV s–1 (~11 h for one cycle).
Figure S2. X-ray diffractograms for a ~300-nm-thick WO3 thin film subjected to the shown treatments. Intercalation and de-intercalation of Li ions took place at 0.1 mV s–1. Intensities are shown in arbitrary units (a.u.) and curves are vertically displaced. Dashed red lines mark peak positions originating from the ITO coated onto the glass substrate. No distinct diffraction features can be assigned to WO3 which hence is amorphous irrespectively of treatment.
Figure S3. Current density vs. time during potentiostatic de-trapping at the shown potential, and for the shown time periods, of a ~300-nm-thick WO3 film.
Figure S4. (a) Charge capacity of a ~300-nm-thick WO3 film after the following electrochemical operations: (I) 10 cyclic voltammetry (CV) cycles were run in the range of 2.0–4.0 V vs. Li/Li+ with a scan rate of 20 mV s–1 followed by a resting period of 10 minutes, then (II) 20 CV cycles were run in the range of 1.5–4.0 V vs. Li/Li+ with a scan rate of 10 mV s–1 followed by galvanostatic de-trapping at a current density of ~3.0 μA cm–2 for 2 h, and finally (III) another 10 CV cycles were run as in (I) followed by de-trapping as before. (b) In situ optical transmittance at a wavelength of 550 nm recorded concurrently with the measurements in (a); inset is a close-up view of transmittance modulation during (III). Note that the horizontal axes differ in (a) and (b).
