Deciphering Molecular Doping in Organic Materials Using Multiscale Simulations
Abstract
Approved for Public Release-Organic semiconductors (OSCs) play a critical role in addressing multiple Naval Science and Technology Priorities including Code 33 (Mission Capable, Persistent, and Survivable Naval Platforms), for which OSC-enabled flexible photovoltaic energy production is essential, as well as Code 34 (Warfighter Performance), for which OSC biomaterials are an emerging health monitoring paradigm. The electronic conductivity of OSCs in these applications is crucial to their functionality, with the addition of molecular dopants being a ubiquitous strategy for enhancing performance. Although nascent design strategies have emerged for tailoring OSC-dopant interactions, the field lacks predictive doping paradigms due to the complex interplay of OSC-dopant miscibility, morphology, electronic structure, and charge transport. Experimental identification of performance descriptors is obstructed by structural disorder present at multiple length scales, as well as the strong sensitivity of doping to morphology and processing. These difficulties are further compounded by the lack of scalable molecular modeling methodologies for characterizing electronic and morphological structure at mesoscopic length scales. Advancing the understanding of OSC-dopant interactions requires the development of modeling methodologies that connect molecular scale electronic structure with mesoscale morphology. Here, we propose to address this methodological gap by developing the coarse-grained doping (CGD) model. Application of the CGD model to a canonical molecularly doped conjugated polymer system (P3HT:F4TCNQ) will facilitate accurate predictions of morphology, doping efficiency and charge carrier transport over the experimentally relevant 10-100 nm length scale. The specific goals of this project are: (1) implement and validate a CGD model for P3HT:F4TCNQ; (2) characterize the interplay of polymer conformation and doping efficiency in the solution-phase of co-deposited P3HT:F4TCNQ; and (3) characterize morphology, doping efficiency, and charge mobility in sequentially vapor-doped films of P3HT:F4TCNQ. Successful completion of these goals will address the methodological gap between electronic and mesoscale modeling in molecularly doped OSCs, enabling in silico knowledge generation and rational design. These capabilities will advance the research priorities of the Navy by facilitating the design of flexible electronics technologies in which molecular dopants are commonly employed to enhance photovoltaic, luminescent, transistor, and sensor performance.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 15, 2023
- Source ID
- N000142312542
Entities
People
- Nicholas E Jackson
Organizations
- Office of Naval Research
- United States Navy
- University of Illinois Urbana–Champaign