ANSER Research Areas

The ANSER Center focuses on two basic research thrusts in its transformational work in the field of solar energy.

Research Subtask 1: Molecules, Materials, and Systems for Solar Fuels

Our greatest challenge is efficient fuel production at acceptable rates and driving forces. The ANSER Center is employing a hierarchical approach to understanding catalyst and photocatalyst function; thus, requiring a level of integration that cannot be achieved by any single research group. ANSER Center catalyst discovery is strongly hypothesis-driven, nicely complementing but not duplicating the approach of our collaborator, the DOE Joint Center for Artificial Photosynthesis (JCAP) Energy Innovation Hub.

The ANSER Center emphasizes catalysts ranging from molecules, to clusters, to nanoparticles, to bulk materials that: a) are derived from plentiful elements, b) have promising compositions that are thermodynamically inaccessible as bulk (macroscopic) materials, and c) may enable access to new mechanistic pathways, thereby moving beyond perceived fundamental or practical limits on catalyst 

performance, including catalyst kinetics and overpotentials. 

Subtask 1 is organized around four cross-cutting subjects:

• Focus 1: Organic/Inorganic/Hybrid Light Harvester
• Focus 2: Water Oxidation Catalytic Systems
• Focus 3: Water Reduction Catalytic Systems (e.g. Figure 1)
• Focus 4: Carbon Dioxide Reduction Catalytic Systems

Figure 1: Photocatalytic proton reduction by molecular catalysts in solution via electron transfer from a purpose-synthesized organic chromophore bound to a semiconductor surface.

Research Subtask 2: Molecules, Materials, and Systems for Solar Electricity

ANSER Center research tests theory-driven ideas to understand at a fundamental level how photovoltaic cell performance is affected by nanoscale/mesoscale architectural-electronic structure relationships in soft-matter and in hybrid soft-matter/hard-matter solar cells, photon capture, exciton creation and decay, exciton dissociation/quenching, and charge transport, electrode microstructure, doping, and surface chemistry.

Photovoltaic cells fabricated from relatively simple, non-toxic, earth-abundant, mechanically flexible, and low-cost materials offer the prospect of efficient large-scale solar electricity production. Efficiencies have advanced dramatically in the past five years, driven by an ever-increasing, but by no means complete, understanding of the relevant chemistry, materials science, physics, and performance limits. A closely integrated, highly productive interplay of synthesis, characterization at multiple time and length scales, and theoretical analysis and prediction, led to a number of ANSER Center “firsts” in materials design, mechanistic understanding, and performance metrics.

ANSER Center research is testing ideas driven by theory to understand at a fundamental level how photovoltaic cell performance is affected by nanoscale/mesoscale architectural-electronic structure relationships in soft-matter and in hybrid soft-matter/hard-matter solar cells, photon capture, exciton creation and decay, exciton dissociation/quenching, and charge transport, electrode microstructure, doping, and surface chemistry. Understanding these phenomena feeds back directly to developing light capture and charge delivery strategies to power solar fuels catalysts as well.

Following the same interactive method of study as described in Subtask 1, ANSER’s ongoing Subtask 2 solar electricity research is organized around the following cross-cutting subjects:

• Focus 1: Perovskite-based Hybrid Solar Cells (e.g. Figure 2)
• Focus 2: Active Layer Polymer/Small Molecule Structure-exciton Dynamics
• Focus 3: Fullerene Acceptor Uniqueness and Designed Replacements
• Focus 4: New Interfacial Materials and Phenomena
• Focus 5: Unconventional Carbon Nanomaterial and Metal-organic Active Layers

Figure 2: (a) Photo of an encapsulated low-temperature vapor-assisted solution processed device and a cross-sectional scanning electron micrograph of a functional device and (b) current-voltage characteristics of lead-free perovskite devices.