Polythiophene–PCBM-Based All-Organic Electrochromic Device: Fast and Flexible

Abstract

A fast and flexible all-organic electrochromic device, fabricated using polythiophene and PCBM as active materials and plastic substrate, which shows very good power efficiency as well, has been reported here. The device shows quantifiable improvement in electrochromic performance using parameters like switching speed, coloration efficiency, color contrast, and cycle life. Spectroscopic investigations have been carried out using Raman and UV–vis to establish a bias induced redox switching based mechanism for the reported improvement in the performance. The device shows switching between magenta (OFF) and transparent states (ON) with a very small bias of ±1 V, an optical modulation of 50% and an absorbance switching contrast of 91%. An enhanced stability for a duration of longer than 2500 s and 250 cycles has been reported with an ultrafast response of few hundred milliseconds. A very high coloration efficiency of 321 cm2/C is achieved, making the proposed device one of the best reported P3HT-based electrochromic devices.

Chronopotentiometric Deposition of Nanocobalt Oxide for Electrochromic Auxiliary Active Electrode Application

“…Electrochromism, the phenomenon of bias‐induced reversible color change, is one of the most exploratory areas. [ 1–12 ] Any material may have electrochromic (EC) properties [ 13 ] but only the ones with appreciable switching time, [ 14 ] coloration efficiency, [ 15 ] contrast ratio, [ 16 ] and quality factor may be used in an actual device in smart windows, displays, etc. and often depend upon the active materials’ properties.…”

“…[ 20 ] Recent research related with electrochromism is being done with a focus on fabricating various materials for EC devices for less consumption of energy. This is done by different device design paradigms like all‐organic, [ 16 ] all‐inorganic, [ 21 ] and hybrid (inorganic–organic) paradigms. [ 22,23 ] It is important here to mention that EC devices have applications beyond color switching which include energy‐storage devices, [ 24 ] memory device, [ 25 ] heat shielding, [ 26 ] etc.…”

Prussian blue‐based inorganic flexible electrochromism glucose sensor

“…Electrochromic devices are known for reversibly changing their optical properties (reflectance/transmission/absorbance) under external applied bias and the materials exhibiting such properties are termed as electrochromic materials [10][11][12][13]. In addition to the multifunctional property, flexible electrochromic devices have an additional feature of deformation making them potentially useful in curved windows, military camouflage, etc [14][15][16].…”

Improved ionic solid/viologen hybrid electrochromic device using pre‐bleached Prussian‐blue electrode

“…Actual mechanism behind electrochromic operation must be known to improve performance which varies depending on the material category such as organic [20], inorganic [21], coordination network complex [22], metallo-organic [23,24] etc. Prussian blue (PB) [25,26], an important coordination compound, has been explored for its electrochromic performance since 1978.…”