Spectrally Selective PANI/ITO Nanocomposite Electrodes for Energy-Efficient Dual Band Electrochromic Windows

Abstract

Glazing employing electrochromic materials can change their optical characteristics of transparency and absorption of solar radiation according to users' needs by simultaneously reducing visible light and NIR transmission through the window. However, spectral selectivity has been becoming a key requirement in smart dynamic windows as it permits maximizing both visual and thermal comfort while minimizing energy consumption for heating, cooling, and lighting. Herein, a dual band electrochromic system is presented, which consists of an engineered nanocomposite electrode capable of advantageously combining the broad band plasmonic response of nanocrystalline indium-tin-oxide with high optical contrast of polyaniline. Their synergistical spectroelectrochemical features make possible the implementation of a four-state tunable electrochromic system (here referred to as "plasmochromic"), which permits selectively regulating optical transmittance in the visible and near-infrared range and exhibits excellent spectral selectivity (the ratio between visible light transmittance (T LUM ) and solar transmittance (T SOL ) can be tuned from 0.67 to 1.61) across a potentials window of only 1.2 V.

Recent Advances on Dual‐Band Electrochromic Materials and Devices

“…The excellent optical behavior of the composite was ascribed to the high active surface area and the efficient interfacial charge transfer between ITO and PANI. [127] Dual-band modulation effects have also been reported from the hybrid system combining EC and TC properties of organic and inorganic components. Liang et al presented a novel hybrid system composed of electro-responsive liquid crystals (LCs) micro-domains and thermo-responsive W-VO 2 NCs, which offered four different optical modes under different temperatures and various external voltages.…”

“…The excellent optical behavior of the composite was ascribed to the high active surface area and the efficient interfacial charge transfer between ITO and PANI. [ 127 ]…”

“…b) Illustration of the four distinct dual-band EC modes. Reproduced with permission [127]. Copyright 2020, American Chemical Society.…”

A Systematic Review of the Most Recent Concepts in Smart Windows Technologies with a Focus on Electrochromics

“…The advances in the field of spectrally selective EC systems were reported by many researchers. Yilmaz et al [72] have used nanocrystalline ITO (indium-tin-oxide) with high optical contrast of polyaniline (PANI). Laboratory-scale sandwich EC devices were fabricated "using the PANI/ITO nanocomposite film as the active working electrode and a mesoporous CeO 2 film (thickness ∼350 nm) as the counter electrode".…”

3D Pine‐Needle‐Like W18O49/TiO2 Heterostructures as Dual‐Band Electrochromic Materials with Ultrafast Response and Excellent Stability

“…[ 20,21 ] One is to directly use single component EC materials with dual‐band response, such as doped TiO 2 nanocrystal, which can simultaneously modulate NIR light by localized surface plasmon resonance (LSPR) absorption at high voltages and VIS light by polaronic absorption at lower voltages. [ 22,23 ] However, the preparation of doped TiO 2 nanocrystals was complicated and costly. It is necessary to strictly control the surface chemistry of nanocrystals and the pore size between nanocrystals because nanocrystal–electrolyte interfacial contact or the movement of ions in micropores would significantly affect LSPR performance.…”