![Page 1: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/1.jpg)
Norman Ferrer Valls
Iván López Lliberós
![Page 2: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/2.jpg)
Introduction
Organic semiconductors
Electrochromic technologies
• Liquid crystal
• Liquid crystal display
• Viologen
• Viologen + TiO2
• WO3
Electrochromic applications
Conclusions
![Page 3: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/3.jpg)
Introduction Semiconductors form the basis of electronic
devices.
Conventionally semiconductors:
• Silicon
• Germanium
• Selenium
• Aluminium
Great progress with organic and hybrid materials as
semiconductors.
![Page 4: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/4.jpg)
Organic semiconductors
Polymers are naturally insulated.
Through the interaction of alternating single and
double bonds, is created a space between the
valence band and conduction band.
Doping: achieves the
creating of free carrier
Acting either oxidation or reduction
Radical cations or anions are formed
Doping -> Add or remove electrons in the polymer
chain through a redox reaction.
![Page 5: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/5.jpg)
Conjugated polymers with delocalized -electron
systems behave as model organic semiconductors
Organic semiconductors
![Page 6: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/6.jpg)
Examples:
Organic semiconductors
![Page 7: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/7.jpg)
Apps
OSC
OLED
ELECTROCHROMIC
OFET
Organic semiconductors
![Page 8: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/8.jpg)
Electrochromic devices • Is the reversibly ability of a material to change
its colour by an electrochemical oxidation or reduction reaction, caused by the application of an electrical potential.
Electrochromism
●“Thermochromism” and “photochromism” describe
changes of colour produced by heat and light.
![Page 9: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/9.jpg)
Electrochromic devices
●Visible spectrum:
Transmittance (T) Reflectance (R)
Absorptance (A) Emittance (E)
When thin film of electrochromic materials are integrated in devices, it becomes possible to modulate
![Page 10: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/10.jpg)
Electrochromic devices
●Goal -> Achieve different wavelengths associated
to variable potential.
![Page 11: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/11.jpg)
Electrochromic devices
![Page 12: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/12.jpg)
Electrochromic devices
Liquid crystal
![Page 13: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/13.jpg)
Electrochromic devices
Liquid crystal display
![Page 14: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/14.jpg)
Electrochromic devices
The image describes the synthesis
of aelectrochromic ionic liquid
(IL) based on a phosphonium core
tethered to a viologen moiety.
The electrochromic platform
exhibits a coloration efficiency of
10.72 cm2 C−1 and a varied
optical output as a function of the
incident current.
Viologen:
![Page 15: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/15.jpg)
Electrochromic devices ● Viologen display functionalized with TiO2: an
electrochromic display based on an electrolyte
consisting of an aqueous solution of a dipositively
charged organic salt, containing a colourless cation
that undergoes a one-electron reduction process to
produce a purple radical cation, upon application of
a negative potential to the electrode.
![Page 16: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/16.jpg)
Electrochromic devices
The device is made up of 5 layers, whose
composition is:
Plastic or glass
Conductive substrate +
Electrochromic layer
Electrolyte
Conductive substrate + Ion
storage layer
Plastic or glass
![Page 17: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/17.jpg)
Electrochromic devices ●The nature of direct current preserves the relatively
unstable monocationic radical.
●This change in spectral features explains the
prolonged optical memory.
●This effect could be used to make a prolonged
darkened state.
![Page 18: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/18.jpg)
Electrochromic devices
![Page 19: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/19.jpg)
Electrochromic devices WO3 A metal cation ( Li+ normaly ) which intercalates WO3
grid when it is reduced by an applied external
voltage. Positive ions that were stored in the counter
electrode layer , cross the ion conductor layer to reach
the electrochromic material when it receives an
electrical current. This chemical reaction produces
changes in the UV - visible spectrum of WO3.
![Page 20: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/20.jpg)
Electrochromic devices
Some applications…
Smart windows
Welding shields https://www.youtube.com/watch?v=OpZUN3dd51s
Rearview mirrors of
cars
![Page 21: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/21.jpg)
Conclusion
ADVANTAGES DISADVANTAGES
Lifetime (cycles)
Refresh capacity
Technology
developing in
progress
Memory
Little potential for use
Pronounced optical
contrast
Reversibility
Improve the quality of
life of people in
different areas
![Page 22: Norman Ferrer Valls Iván López Lliberós student presentations... · Electrochromic devices •Is the reversibly ability of a material to change its colour by an electrochemical](https://reader034.vdocuments.us/reader034/viewer/2022042909/5f3b1dfa72d3ba5629244f77/html5/thumbnails/22.jpg)
Is everything clear or are you a little
chromic…?
Thank you!