Research Impact on Emerging Quantum Materials for Electrochromic Applications

Abstract

Electrochromic devices (ECDs), which can dynamically vary optical properties under applied specific voltage, have been actively studied for use in applications requiring human comfort and energy efficiency (i. e. smart windows and electronic displays). In order to improve the electrochromic (EC) performances, many researchers have been using nanomaterials. In this respect, in the present study, we highlight some of valuable examples using WO3 from unique nanostructures to quantum dots (QDs) and discuss the core relationship between nanostructuring and EC performances. In particular, the present study proposes major impact on the novel approach using QDs to upgrade technical value and application of ECDs.

Electrophoretically-Deposited CdSe Quantum Dot Films for Electrochromic Displays and Smart Windows

“…Quantum dots (QDs) can accumulate external electrons on their electron levels in a process called QD charging or doping via chemical, , photochemical, − and electrochemical routes. − The electrochemical approach appears to be the most attractive one since it allows controlling the number of injected electrons by the electrode potential and reversible switching between charged and uncharged (doped/undoped) states. Such switching provides pronounced electrochromism in QDs, making electrochemical charging suitable for various practical applications such as smart windows and displays. , Besides practical applications, electrochemical charging can be used to determine the position of energy levels , in QDs, to study exciton recombination processes as well as the influence of localized surface traps on the optoelectronic properties of QDs …”

“…Such switching provides pronounced electrochromism in QDs, making electrochemical charging suitable for various practical applications such as smart windows and displays. 15,16 Besides practical applications, electrochemical charging can be used to determine the position of energy levels 17,18 in QDs, to study exciton recombination processes 19 as well as the influence of localized surface traps on the optoelectronic properties of QDs. 12 Electrochemical charging has been studied in several quantum-confined structures including CdSe, [6][7][8][9][10]13,14,20,21 PbSe, 22,23 ZnO, 11,24 HgX (X = S, Se, Te), 18,25 CuS, 26 InP/ ZnSe/ZnS, 27 CdSe/CdS and CdSe/CdS/ZnS core and core− shell QDs.…”

Review: smart windows based on photonic crystals

“…The essence of this discoloration is the difference in optical performance (transmittance, reflectance and absorptivity) due to the change in the valence state of ions [77][78][79][80]. The performance indexes for evaluating electrochromic smart windows are mainly optical contrast, response time, coloring efficiency and cycling stability [81][82][83]. Optical contrast is the most basic performance index of electrochromic materials, which refers to the difference in optical transmittance of an electrochromic material in colored state and bleached state.…”