Multifunctional thermo-electrochromic devices based on 2D perovskite gel electrolyte

The development of multifunctional materials is an expanding research field, driven by the demand for adaptive systems capable of responding dynamically to environmental stimuli. In this work, we present a thermo-electrochromic device (TECD) exploiting a perovskite-based thermochromic material, which functions as both the electrolyte and thermochromic layer within a standard electrochromic architecture. The material consists of a hybrid gel composite made of block co-polymer (Pluronic L61), lead iodide, and n-butylammonium iodide, designed for independent thermal and electrical activation. To optimize the gel formulation, we adjusted the weight ratio between Pluronic L61 and perovskite precursors, successfully lowering the thermochromic transition temperature compared to previous results. Differential scanning calorimetry (DSC) and electrochemical impedance spectroscopy (EIS) were employed to assess transition temperature and ionic conductivity, identifying the optimal formulation for device integration. The resulting TECD operates in four distinct optical states, demonstrating a maximum transmittance modulation of 75.2 % in the visible spectrum, along with fast switching kinetics and stable cyclability at both room temperature (RT) and high temperatures (≈80 °C). While further optimization is required to enhance performance, particularly by reducing the thermochromic transition temperature, our findings mark a significant step forward in the development of smart multifunctional materials for next-generation adaptive optical devices.