CPF 1: Hybrid materials for efficient photon-to-electron conversion
PI: Edward H. Sargent (University of Toronto, Canada), Iain McCulloch, Frederic Laquai, Udo Schwingenschlögl, Aram Amassian, Stefaan De Wolf, Derya Baran, Thomas Anthopoulos
Here we propose to advance and investigate, in partnership with KAUST colleagues, the materials physics and chemistry of such materials; and to carry out together the device engineering to develop high-performance next-generation photon-to-electron conversion solutions. The work emphasizes solar cells but also includes thermoelectrics and photodetectors.
This proposal includes new perovskite and quantum dot (QD) device designs and preparation schemes, experimental and computational studies of materials photophysics and the development of tandem solar cells, thermoelectrics and photodetectors. We will explore new perovskite compositions by designing and synthesizing new organic cations and by obtaining in-depth understanding of the impact of crystal structure/composition on the optoelectronic properties. We will fabricate perovskite-based single-junction and tandem devices, and further engineer these devices toward record performance. We will prepare QDs with optimized elemental composition and surface ligands that emit at infrared region and develop device architectures for thermoelectric and sensing applications.
CPF 2: Design of tandem CO2 electroreduction catalysts to produce renewable fuels and feedstocks
PI: Edward H. Sargent (University of Toronto, Canada), Mohamed Eddaoudi, Iain McCulloch, Lance Li, Luigi Cavallo, Yu Han
This proposed research project will combine nanoscale materials engineering, computational modeling, and advanced spectroscopic techniques to discover high-performance catalysts for the electrochemical conversion of CO2 to renewable fuels and feedstocks. This project will have three interconnected themes which will operate in synergy - catalyst development, computational design, and spectroscopic investigation. We will combine different materials systems such as 2D transition metal dichalcogenides (2D TMDs), metal organic frameworks (MOFs), and nanostructured metal electrodes (NMEs) to accomplish tandem catalysis to C2+ hydrocarbons. We will firstly develop and test the catalytic activity of each material system and then design synthetic approaches to interface different materials systems together. This approach allows for a wide search space which will require computational predictions coupled with spectroscopic investigation to optimize the catalysts for a specific target product.
CPF 3: Scalable III-V growth by Bridgman gradient thin-film VLS
PI: Ali Javey (UC Berkeley, USA), Stefaan De Wolf
Our proposed collaborators in this project, the Javey lab at UC Berkeley, recently invented a novel method – the thin-film vapor-liquid-solid (TF-VLS) growth mode – for inexpensive growth of III-V materials at scale. This development has the potential to enact transformative change in photovoltaics, as high-efficiency III-V materials can be grown using this method at low costs, and on application-specific substrates. Preliminary results with typical TF-VLS InP material, while promising, have demonstrated direct impact of parasitic limitations introduced by grain boundaries and optoelectronic nonuniformity, so a clear path to improvement of TF-VLS devices is available for study as they increase in scale. With this partnership, we hope to expand activity in this topic to enable further exploration of scalable III-V photovoltaics, utilizing a unique combination of facilities and expertise between our two institutions. First, the implementation of thermal gradient growth techniques in combination with the TF-VLS growth mode would enable significant advantages in terms of nucleation and therefore grain boundary control, with the eventual goal of single-crystal thin films still grown by the highly scalable TF-VLS process on nonepitaxial substrates. Second, development of process cost reductions and compatibility improvements by way of low-temperature precursor plasma cracking would represent a significant step forward in the implementation of the TF-VLS technique alongside industry-standard systems, such as scalable, novel III-V/Si tandem structures. The specific expertise in TF-VLS process design the Javey group brings would be critical for this development and would be highly complementary to the unique facilities present in the KAUST Solar Center. Lastly, the two proposed tasks for our collaborative process would themselves be synergistic, as the proposed gradient TF-VLS growth technique can certainly be combined with an optimized low-temperature TF-VLS process to form high quality, scalable III-V films compatible with a wide range of processes and applications.
CPF 4: Thermodynamic properties of KAUST materials and their impact on non-fullerene ternary organic solar cells
PI: Harald Ade (North Carolina State University, USA), Derya Baran, Aram Amassian, Frederic Laquai
Our goal is to accelerate materials design and optimize development of ternary organic solar cells (OSC) suitable for high efficiency and stability, by delineating experimentally the fundamental, thermodynamic-driven structure-function and structure-stability relationships of the active layers. To realize this goal, we will employ a number of novel methods developed by the Ade group.
The advancement of organic solar cells (OSCs) using non-fullerene acceptors (NFAs) in binary and ternary systems is a key current research direction of the KAUST Solar Center (KSC). The Center projects heavily rely on the design of new organic molecules with tailored properties for use in OSCs with ~12% efficiency now achieved and a path to 18% within reach. However, current structure-function analysis provides mostly “post-mortem” morphology characterization and heuristic correlations to processing conditions. Such efforts often only give ad-hoc explanatory and not yet predictive relations to molecular structure. The resulting wide-spread trial-and-error approach has been labor intensive and restrained progress. Thus, the development and processing of new compounds are ideally guided by understanding of the thermodynamically achievable OSC morphology and its stability. To provide such guidance, we propose a collaborative project with the Ade group (North Carolina State University), which has developed novel soft x-ray characterization tools and novel quantitative models for structure-miscibility-function relations in OSCs (Nature Materials, Nature Photonics, under review, respectively). These advances are based on the experimental determination of the Flory Huggins interaction parameter, χ, and its impact using resonant soft x-ray scattering (R-SoXS), scanning x-ray microscopy (STXM), and Dynamic Secondary Ion Mass Spectrometry (DSIMS). Together, these measurements allow to screen materials combinations for their suitability as a high-efficiency OSC system, optimize processing strategies, and predict stability. The characterization by the Ade group will complement the synthetic (McCulloch and Beaujuge groups), device optimization and characterization (Baran and Amassian groups) and spectroscopic (Laquai group) efforts of KSC. The target of these activity will be: i.) determination of χ for a number of donor:non-fullerene acceptor (NFA) binary systems and delineation of their implications in the ternary systems, ii.) exploration of the stability within a well-defined hypothesis and paradigm that the most stable devices have mixed amorphous domains that have compositions close the percolation threshold and correspond to the binodal composition.
CPF 5: Theoretical design of non-fullerene acceptors for organic solar cells
PI: Denis Andrienko (Max Planck Institute for Polymer Research, Mainz, Germany), Derya Baran, Frederic Laquai, Iain McCulloch
To complement the synthetic (McCulloch and Beaujuge groups), device optimization and characterization (Baran group) and spectroscopic (Laquai group) efforts of the Center, we propose a collaborative project with the group of Dr. Denis Andrienko (Max Planck Institute for Polymer Research, Mainz, Germany). Dr. Andrienko's group develops simulation tools and methods targeting energetics of organic-organic interfaces, binding of charge transfer states, prediction of open circuit voltage, and, more general, electrostatic effects in organic semiconductors.
The objectives of this theoretical/simulation activity will be: i.) pre-screening of efficient dyes and oligomers synthesized in the Center (e.g., based on thienobenzothiophene) and alternative acceptors (e.g. structures based on anthracenedithiophene/benzothiadiazole-based structural motifs), ii.) exploring the mesoscale morphology (i.e. structure of organic-organic interfaces) in order to improve solar cell efficiencies, iii.) calculation of CT-state energies and dynamics to complement the (ultrafast) spectroscopic activities of the Center.