TOSCA Thrust II: Predicting Long-Term Stability for Organic Solar Cells through Physical Properties of Photovoltaic Materials
Abstract
Mission needs and research opportunity. With single layer Organic Solar Cells (OSCs) now reaching an efficiency of 17.4% (Official NREL chart) and efforts underway worldwide that likely lead to efficiencies of >20% within the next 2 years, the deployment of OSCs as flexible electric power sources with high power/weight ratios can now be envisioned ever more clearly.Performance parameters other than power conversion efficiency (PCE) are now demandingattention and solutions. Specifically, understanding and controlling the stability and robustness of OSCs has become a paramount concern for eventual OSC deployment in the battlefield and society at large.Objective. Our objective is to develop and deploy a multi-pronged approach to delineate and control the fundamental science of the main factors of performance degradation associated with the OSC active layer, such as those related to the morphology, donor-acceptor interfaces, and photochemistry. Instabilities and device degradation related to interlayers, electrodes, and otherdevice aspects will not be investigated. Systems targeted for deep and comprehensive understanding are based on semi-conducting donors and non-fullerene small molecule acceptors (NF-SMA) with high efficiency and representative molecular structures.Overall approach: This joint proposal in build on a foundation of four research thrusts, each of which has a distinct and complementary focus and approach towards the common goal of understanding, controlling, and increasing device stability. While distinct and administrated as separate grants to four groups, these thrusts are strongly coordinated with each other. One significant common thread is the comprehensive study of the same materials systems to yielddeeper understanding than individual studies on separate systems could achieve. This coordination is captured and formalized by the creation of the Triangle Organic Solar Cell Alliance (TOSCA), which comprises the groups of W. You (UNC), H. Ade, A. Amassian, D. Dougherty, K. Gundogdu, B. O~Connor, and F. So (NCSU). The four thrusts within TOSCA focus on novel materials synthesis (You), thermodynamics and mechanical properties (Ade, O~Connor), functional imaging of interfaces and morphological characterization (Amassian, Dougherty), and spectroscopic characterization of device physics and defects (So, Gundogdu). TOSCA will have coordinated activities that range from collaborative research supported by joint group meetings and semi-annual Triangle-wide workshops, to the selection of seminar speakers at NCSU and UNC that serve to accelerate the science articulated below. TOSCA will also target organization of national workshops (to be supported with separate funds) to help chart the future of OSC research in the Nations in the context of National security and economic needs. TOSCA intends to create and utilize a full feedback loop within the alliance in which novel materials and key reference systems are characterized in detail to understand their performance and sources of instability to a point that it will allow implementation of solutions. Complementary expertise in quantum chemical calculations and molecular dynamics simulations will be sought through collaborations. Importantly, such knowledge and understanding will then lead to improved materials design with improved intrinsic stability.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 11, 2020
- Source ID
- N000142012155
Entities
People
- Harald Ade
Organizations
- North Carolina State University
- Office of Naval Research
- United States Navy