DMREF: Collaborative Research: Organic Semiconductors by Computationally-Accelerated Refinement (OSCAR)

Princeton University, Princeton NJ

Investigators

Abstract

NON-TECHNICAL DESCRIPTION: The performance of materials in a wide array of device types - light-emitting materials for displays, semiconducting compounds for transistors, light-absorbing materials for solar cells - is directly related to the way the atoms or molecules are arranged in the solid-state. A major hurdle to the discovery of new molecules for these applications is the complete lack of metrics to correlate the structure of a molecule with its likely solid-state order. This highly collaborative project, combining researchers with expertise in chemistry, engineering, and physics, will accelerate the development of new electronic and energy materials by developing computational models to predict solid-state order for a common class of high-performance materials. With this model in hand, new molecular structures with optimal electronic and optical properties will be predicted and prepared, eliminating the wasted time, effort, hazards, and waste-generation associated with current synthesis and screening protocols. This interdisciplinary project will provide training to graduate and undergraduate researchers in a wide array of marketable skills, ranging from computation through synthesis to electronic device fabrication. As the computational models develop, 3-D printing technologies will be used to provide hands-on models of the molecular packing arrangements studied in this project as demonstrators for industrial and academic facility tour groups. TECHNICAL DESCRIPTION: Silylethyne-functionalized aromatics are common soluble organic semiconductors used in transistors, photovoltaics, sensors, and diodes. Very subtle changes to the alkyl groups of the silylethyne substituent can yield substantial improvement in performance by their manipulation of solid-state order, but the current Edisonian approach to this type of tuning is time-consuming and wasteful. The OSCAR program will develop a robust computational model to predict solid-state order as a function of alkyne functionalization for this successful class of molecular semiconductors. Coupling structural predictions with computational evaluation of properties, such as charge-transfer integrals, will yield an iterative model capable of predicting the ideal molecular substitution for optimum solid-state charge-carrier mobility. The computational model will be validated by synthesis, structural analysis, and device characterization and measurement. Feedback from experimental studies will further strengthen the computational models. Final validation of the approach will involve application of the silylethyne functionalization strategy to previously un-studied chromophores, to yield a robust structure-predicting package to be made available to the scientific community at large.