Chemistry

Materials science

Photocurrent

Stacking

Optoelectronics

Conjugated system

Polymorphism (computer science)

Composite material

Biochemistry

Physics

Transistor

Nanotechnology

Organic chemistry

Gene

Quantum mechanics

Organic electronics

Photoluminescence

Genotype

Voltage

Band gap

Polymer

Nature Communications

Polymorphism of organic semiconducting materials exerts critical effects on their physical properties such as optical absorption, emission and electrical conductivity, and provides an excellent platform for investigating structure–property relations. It is, however, challenging to efficiently tune the polymorphism of conjugated polymers in aggregated, semi-crystalline phases due to their conformational freedom and anisotropic nature. Here, two distinctly different semi-crystalline polymorphs ( β 1 and β 2 ) of a low-bandgap diketopyrrolopyrrole polymer are formed through controlling the solvent quality, as evidenced by spectroscopic, structural, thermal and charge transport studies. Compared to β 1 , the β 2 polymorph exhibits a lower optical band gap, an enhanced photoluminescence, a reduced π-stacking distance, a higher hole mobility in field-effect transistors and improved photocurrent generation in polymer solar cells. The β 1 and β 2 polymorphs provide insights into the control of polymer self-organization for plastic electronics and hold potential for developing programmable ink formulations for next-generation electronic devices.

Impact of polymorphism on the optoelectronic properties of a low-bandgap semiconducting polymer