By combining computational aided design with synthetic chemistry, we are able to identify core 2D polyaromatic small molecule templates with the necessary optoelectronic properties for p- and n-type materials. By judicious selection of the functional groups, we can tune the physical properties of the material making them amenable to solution and vacuum deposition. In addition to solubility, we observe that the functional group can influence the thin film molecular packing. By developing structure-property relationships (SPRs) for these families of compounds we observe that some compounds are better suited for use in organic solar cells, while others, varying only slightly in structure, are favoured in organic field effect transistor devices. We also find that the processing conditions can have a dramatic impact on molecular packing (i.e. 1D vs 2D polymorphism) and charge mobility; this has implications for material and device long term stability. We have developed small molecule p- and n-type materials for organic solar cells with efficiencies exceeding 2%. Subtle variations in the functional groups of these materials produces p- and ntype materials with mobilities higher than 0.3 cm2/Vs. We are also interested in using our SPR approach to develop materials for sensor and bioelectronic applications.
Collis GE (2015) Designing small molecule polyaromatic p- and n-type semiconductor materials for organic electronics. Micro+Nano Materials, Devices, and Systems. Available: http://dx.doi.org/10.1117/12.2202565.
Research was undertaken through CSIRO’s Flexible Electronics Theme. ABH, GEC, YS, SM, and AB acknowledgeCSIRO OCE for financial support. The author acknowledges all the work and effort of the co-authors on thesepublications from CSIRO, the Australian Synchrotron, and Australian (University of Melbourne, Monash University,University of Newcastle and University of Warwick) and international collaborators (Wake Forest University, USA;Georgia Institute of Technology, USA; and King Abdullah University of Science and Technology, KSA).