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Transcript of P3HT PowerPoint
Godwin St. Luce
PhD in Engineering, Micro/Nanoscale Emphasis
MSE 504 1
*Applications of P3HT
MSE 504 2
• History
• Introduction
• Properties
• Applications
• Advantages and Disadvantages
• Conclusions
• References
• Questions
*Overview
MSE 504 3
History* The study of polymers have been around since WWII.
* 1992 Roncali surveyed electrochemical synthesis in Polythiophenes (PTs)
* 1990-1994 Schopf and Kobmehl published “Conductive Polymer Layers”2)
* 1997 Roncali investigated the electronic properties of substituted PTs
* 1998 McCillough’s focused on Chemical Synthesis of Conducting PTs
* 1999 Reddinger and Reynolds general review of Conducting Polymers
* 2000 Alan Heeger, Alan G. MacDiarmind and Hideki Shirakawa received
Nobel Laureates in Chemistry (Conjugated Polymers)[1]
MSE 504 4
• Polymer is a substance containing a large number of repeated structural units join (monomers).
• Polythiophenes is a heterocyclic compound that can become conducting when electrons are added or removed from their structure via doping.
• Poly(3-hexylthiophene-2,5-diyl) known as P3HT is a conducting polymer belonging to the Polythiophenes family.
*Introduction
5MSE 504
*PropertiesConjugated Double Bonds
* As a result of the 3Sp2 orbitals and the lone e- in the (Pz) un-hybridized orbital.
* LUMO is created by the anti-bonding * orbitals and HOMO is created by the bonding orbitals. Their differences is a result of the band gap, of a semi-conductor.
* Energy Band Diagram using polymer as a
semi-conductor active layer [4]
MSE 504 6
*Properties cont’d* Different doping of these polymers can interchange properties. Poly(3-
hexylthiophene) P3HT conductivity at 300K is 30 Scm-1 , where Poly(3-methylthiophene) has conductivity of 500 Scm-1) [3].
* Absorption Spectra of doped and un doped P3HT films @ 300K [3].
MSE 504 7
*ApplicationsP3HT/n-c Si Transistor
* Proposed Energy Band diagram for
n-c Si/P3HT[5].
* Electron Affinity (χ)
* Conduction Band Offset (Δ)
* Valence Band Offset (Δ)
MSE 504 8
*ApplicationsOrganic Light Emitting Diode (OLED)
* Solid-state devices composed of thin films of organic molecules
* Color of light depends on type of organic
molecule in emissive layer (P3HT).
* The intensity of light is proportional to
the applied current.
MSE 504 9
*ApplicationsTypes of OLED
MSE 504 10
*Advantages* Conductive Range of Conductive Polymers [7]
* Very light weight and flexible
* Cost of production
* Availability
* Properties of polymers can be altered drastically by doping.
MSE 504 11
*Disadvantages* In n-doping the added electron is normally lost in the atmosphere.
* Absorption spectra is limited, compared to Si, GaAs etc.
* External Quantum Efficiencies (EQE) are low [6].
* They tend to be much slower than inorganic devices
* Some devices have limited life spans (OLED).
MSE 504 12
*Conclusion* Organic polymers are the new age of electronic research.
* Properties of P3HT are close to being compared with inorganic devices.
* Can be fabricated at room temperature.
* Useful in energy storage application [8].
* Organic material are easy to process in large area.
* Some organic materials are sensitive to oxidation effects.
MSE 504 13
[1] http://www.sigmaaldrich.com/catalog/product/aldrich/698997?lang=en®ion=US
[2] http://doc.utwente.nl/9135/1/t0000022.pd
[3] http://voh.chem.ucla.edu/vohtar/fall04/classes/285/pdf/patil_ch_rev.pdf
[4] http://www.ine.uh.edu/research/organic-solar-cells/index.php
[5] http://144.206.159.178/ft/18414/933128/16265291.pdf
[6] http://nano.teicrete.gr/Microelectronics/Organic%20photovoltaics%20%20technology%20and%20market.pdf
[7] http://www.youtube.com/watch?v=WPcIYr1DkuQ
[8] http://physics.usask.ca/~chang/homepage/Organic/Organic.html
*References
MSE 504 14
*Questions