White Paper Tracking Number: FY2019-0002139-AS Title: Understanding and Enhancing Stability of Perovskite/Contact Interfaces Across Length Scales
Abstract
This 3-year effort will focus on: 1) removal of surface defects at contact/perovskite active layer (PAL) interfaces using robust interface modification schemes; and 2) elucidation of complex degradation chemistries of rapidly evolving, high performing mixed cation halide perovskite activelayers in PV platforms. Printable halide perovskite materials have shown unprecedented advancements in solar energy power conversion efficiencies and have the potential to be manufactured with low cost industrial processing methods. Widespread deployment and commercialization of these technologies is impeded by limited understanding of complex interfacial phenomena at the photoactive layer/contact interfaces, which subsequently limits efficiency and long-term stability. Our approach is based on a holistic, multi-modal tool suite ofcharacterization approaches that allows for molecular-to-nanometer-to-device length scale characterizations of chemical-electronic-physical structure-function relationships. Central to our iterative approach are established photoelectron spectroscopy capabilities and unique, emerging spectroelectrochemical microscopies, which will provide guidelines for the design of Navyrelevantscalable and efficient PAL PV platforms. Of utmost importance is increased understanding of in operando behaviors and subsequent contributions to degradation across length scales. Most perovskite-based degradation studies have focused on materials screening using full devices, overlooking the underlying interfacial chemistries that are device limiting. A major challenge is to connect molecular to nanometer length scale observations with macroscale device performance. To circumvent this challenge, we will combine new measurement science approaches to understand and control chemical interactions at charge selective layer/PAL interfaces. Our iterative approach will enable a direct connection to device performance metrics, thus leading to enhanced performance and stability in halide perovskite-based PVs. In Objective 1, we will focus on the bottom contact, considering both normal and inverted architectures. This will inspire new interface engineering strategies, asoutlined in Objective 2, expanding on our acid-base formulism based on prior results. We will then focus on the top contact in Objective 3, which presents unique challenges due to the spatial heterogeneity that arises from the PAL. Thus, we will undertake a nanoscale characterization approach to determine the best contact approach for HTL or ETL in normal or inverted architectures, respectively. Additionally, we note that improvements in both contacts could result in a return to the bottom contact to repeat the iterative loop, as major problems would have been circumvented thus revealing second order effects.The major outcome of the effort will be design guidelines that ensure enhanced PV efficiencies and stability. A second equally important outcome will be the development of new nanoscale electroanalytical techniques for characterization of printable electronic materials that can be extended to a broad range of opto-electronic platforms that are of interest for Navy missions.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 17, 2020
- Source ID
- N000142012440
Entities
People
- Erin L. Ratcliff
Organizations
- Office of Naval Research
- United States Navy
- University of Arizona