Foredrag ved Dr Roger C. Hiorns, IPREM, Frankrig
Onsdag, 17. januar 2018, SDU, Alsion, lokale U205 kl. 17.00
Organic photovoltaic devices are undergoing a steady revolution in efficiencies and stability. The 10% and 10‐year barriers for lab‐scale materials have long since been broken. A massive challenge remains, however, in transferring this exciting technology to the market place. For fast roll‐to-roll printing, polymers tick all the right boxes, including their applicability to ink‐based technologies. But trying to control their behaviour over large surfaces so that thin layers can be regularly formed is difficult. While large‐scale stabilities are good, large modules (>50 cm2) have efficiencies of around 6% at most, and when going to very large‐scale modules (>1 m2), 3 to 5% is more common.
Block copolymers have been known for decades to improve the structural strength and regularity of polymers. When cast from solution, they form microphase domains of the order of tens of nanometers due to the repulsive tendencies of the constitutive blocks. This scale is perfect for controlling excitonic formation and charge transfer through organic devices. This lecture will give a general introduction to block copolymers for organic photovoltaic devices and then look at some of recent advances in this field.