Electrical devices can be turned on and off through a simple flick off a switch. But what if we wanted to turn chemical molecules on and off like a switch. This is possible using light in what is known as photoswitches. These are molecules that are able to undergo a reversible transformation via irradiation of light. This ability to access the two chemical states leads to different electronic and optical properties which in turn can be exploited in a variety of applications. The photoswitch allows for a nanoscale manipulation of materials using light through having an ON and OFF state.

However we want these photoswitches to response quickly to light switches in order to allow for use in devices. Recent research has been done on a new generation of ultra fast photoswitches where upon light excitation, where they are based on the loss/gain of aromaticity. This leads to fast photoswitching due to the lower energy barrier upon weakening of aromaticity.

My PhD will focus on taking these photoswitches and incorporating them into semiconducting conjugated polymers. These can be thought of as a ‘wire’ with many switches along the polymer that can be turned on and off using light. This is due to a difference in conjugation between the ON and OFF states. This can allow for us to change the charge transporting properties of semiconducting polymer. Once developed we will look into how these materials may be incorporated into bioelectronics devices with the Malliaras group.

Sultaan Yousaf

NanoDTC Student, c2019

Image from https://www.pxfuel.com/en/free-photo-xevli