Doping of Organic Semiconductors

Doped organic semiconductors play an important role in organic electronics, for devices ranging from organic light emitting diodes, solar cells and transistors to thermoelectrics and bioelectronics. For high performance optoelectronic devices, a good ohmic contact between the electrode and the semiconductor layer is required to inject the maximum current density across the contact. Achieving ohmic contacts requires electrodes with high and low work functions to inject holes and electrons respectively. However, it is challenging to produce electrically conducting films with sufficiently high or low work functions, especially for solution-processed semiconductor devices. Most doped polymers suffer from de-doping owing to dopant migration or due to their reactivity in ambient. This talk showcases design strategies in stabilising p- and n-doped organic semiconductors with ultra-high and ultra-low work functions, enabling their processibility in air.  Furthermore, the integration of doped materials and the understanding of their charge transport physics towards the development of high performance organic-based devices and circuits will be presented.