1：Experimental Design and Method Selection:

The study involves fabricating an electrochromic device with a sandwich geometry using P3HT and PCBM as active materials on flexible PET substrates. Spectroscopic (Raman and UV-vis) and electrochemical techniques are employed to investigate the switching mechanism and performance.

2：Sample Selection and Data Sources:

Commercially available chemicals from Sigma-Aldrich and Alfa Aesar are used, including P3HT, PCBM, DCB, ACN, PEO, and LiClO4. Devices are fabricated on both glass and PET substrates for characterization.

3：Devices are fabricated on both glass and PET substrates for characterization. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: UV-vis spectrophotometer (Cary 60, Agilent), Raman spectrometer (LABRAM HR), Keithley 2450 workstation for electrochemical measurements, and materials such as P3HT, PCBM, DCB, ACN, PEO, LiClO4, ITO-coated PET substrates.

4：Experimental Procedures and Operational Workflow:

Solutions of P3HT and PCBM are prepared in DCB using a vortex. Devices are fabricated with layers of PCBM and P3HT on ITO-coated PET, with a LiClO4/PEO electrolyte layer. In situ UV-vis and Raman spectroscopy are performed under applied bias (±1 V) to monitor color switching and vibrational changes. Chronoamperometry and switching kinetics are measured with square wave pulses.

5：Data Analysis Methods:

Color contrast is calculated from transmittance values using a specific equation. Coloration efficiency is determined from optical density and charge density variations. Spectroscopic data are analyzed to identify redox states and mechanisms.