2. POLYSILANES
High molecular weight polymer with silicon in their
backbone
Differ from inorganic polymers like polysiloxane and
polyphosphazene .
The exclusive Si-Si bond allows sigma
delocalization
Electrical and Optical properties and other
Siloxanes
Polyphosphazene Polysilanes
3. • Solubility can be tuned with varying
attached group
• Thermal Resistant upto 573 K
• Sigma electron delocalization along the Si-
Si chain
• Low Sigma-sigma* excitation
• The bond can be broken by UV light
Properties of Interest
4. APPLICATION HISTORY
First Synthesized in 1920
No application till 1970
Yajima et al formation of polydimethysilane to
Silicon Carbide
Discovery of electronic properties by west et al
Two fold:
Application based on the reactivity
Aplication based on the electrical properties
5. APPLICATIONS BASED ON THE REACTIVITY
OF POLYSILANES
Precursor to Silicon Carbide
• Prolysis of a mixture of Polysilanes and
Polycarbosilanes at 1670 K
• Silicon Carbide uses-
Structural Material
Automobile Parts
Heating Material
Steel Production
6. PHOTOINITIATOR IN RADICAL REACTION
Homolytic Cleavage on exposure to UV light
form free silyl radical
Can react with olefinic monomer to initiate
free radical Polymerization
Polymerization of styrene and several
acrylate polymers
7. APPLICATIONS BASED ON THE PHOTOPHYSICAL
AND ELECTRONIC
PROPERTIES OF POLYSILANES
Hole transporting materials
In electronic devices, such as organic light emitting
diodes (OLEDs) and organic photovoltaics (OPV).
8. APPLICATION BASED ON ELECTRICAL
PROPERTIES
Polysilanes in OLEDs
Polysilanes can be employed as hole transporting
materials or emitters in OLED
The basic design of a polymer OLED is
devices, more specifically
in polymer OLEDs.
• OLED in Display and other
Electronic devices.
9. POLYSILANES AS PHOTOVOLTAIC
Polysilane in Photo voltaic
Polysilanes can be part of the active layer
or, such as in multi-layered OLEDs,
serve as a hole transporting hole
transporting material
in organic solar.
10. OTHER AREAS
Fabrication of Microlens Arrays
Coatings
Polysilanes as Photoresists in Microelectronics
And more……
11. CONCLUSION
Application of Polysilanes are numerous
Commercialization has not happened
Some reason:
difficulties in
controlling their synthesis with regard to molecular
weight, PDI and impurities as
well as the high costs of these elaborate methods
and the purification processes involved.
12. REFERENCES
A. Rahimi, Iran. Polym. J., 13, 149 (2004).
A. Rahimi and P. Shokrolahi, Int. J. Inorgan. Mater.,
3, 843 (2001).
J. E. Sheats, Jr., Ch. E. Carraher, Jr., Ch. U.
Pittmann, and M. Zeldin, Macromol.
K. Matyjaszewski, Polym. Mater. Sci. Eng., 64, 104
(1991).
Book Inorganic Chemistry by James E Mark and
Harry E Allock
Modern Synthetic and Application Aspects
of Polysilanes: An Underestimated Class
of Materials? A. Feigl, A. Bockholt, J. Weis