New research from Chalmers University of Technology in Sweden shows how a straightforward adjustment can increase the efficiency of organic electronics two-fold. Organic electronics offer many potential advantages over conventional electronics, which are based on inorganic semiconductors like silicon.
Other examples of organic electronics includes piezoelectric textiles, which are types of types of energy-harvesting materials associated with wearable technology; organic light-emitting diodes (OLEDs); plastic manufactured solar cells; and various innovations in the field of bio-electronics.
With bio-electronics the earliest example was the pacemaker. Since then researchers have focused on using organic materials (materials containing carbon) for interfacing with biological systems. There are several applications in development relating to neuroscience and infection control.
How well organic electronics perform is partly based on doping, whereby additives are woven into a semiconductor to boost its electrical conductivity. This process enables organic based components in solar cells to function.
The doping process works through a redox reaction. With this, a dopant molecule receives an electron from the semiconductor. This activity increases the electrical conductivity of the semiconductor. It follows that the greater the number of dopant molecules a semiconductor reacts with, then the higher the conductivity. A longstanding limitation with this process is that dopant molecules can only exchange one electron each.
This limitation has been overcome, according to lead researcher Professor Christian Müller. He states: “Through this ‘double doping’ process, the semiconductor can therefore become twice as effective.”
This came about by the scientists taking an alternate approach., studying different types of polymers and selecting one with lower ionisation energy. Studies showed the alternate material permitted the transfer of two electrons to the dopant molecule.
The new finding should help to improve the on-going development with organic electronics and to bring forward some technologies that have not advanced due to insufficient energy conversion, including various potential for flexible electronic devices and with thermoelectricity.
The new research has been published in Nature Materials, titled “Double Doping of Conjugated Polymers with Monomer Molecular Dopants.”
