High-Throughput Experimental Approach Capabilities
NREL's high-throughput experimental approach is based on the extensive set of combinatorial synthesis, spatially resolved characterization, and automated data analysis capabilities developed by NREL over the past decade.
Combinatorial Thin-Film Synthesis
We have several physical vapor deposition chambers, and for each we can create intentional, well-controlled gradients in chemical composition, substrate temperature, film thickness, and other synthesis parameters across the substrate, resulting in a material library.
- Combi-1: Oxide- and intermetallic sputtering
- Combi-3: Oxide- and intermetallic pulsed laser deposition
- Combi-4: Chalcogenide (S,Se,Te) and oxysulfide sputtering
- Combi-5: Nitrides and oxynitride sputtering
We also have several non-combinatorial physical vapor deposition chambers, to follow up on targeted synthesis of the most promising materials identified by combinatorial synthesis.
Spatially Resolved Characterization
Each measurement instrument below has an automatically controlled X-Y motion stage that enables mapping of the materials libraries as a function of position, and hence, composition/temperature and other gradients that the material libraries have.
- Composition (X-ray fluorescence, Rutherford backscattering spectroscopy)
- Crystal structure (X-ray diffraction, Raman spectroscopy)
- Optical properties (UV-VIS, FTIR, ellipsometry, photoluminescence)
- Transport properties (4-point probe, Hall effect, Seebeck effect)
- Morphology/microstructure (atomic force microscopy)
- Surface and interface properties (photoemission spectroscopy, Kelvin prove, surface photovoltage, atmospheric photoemission)
- Device performance (J-V measurement under solar simulator)
In addition to these spatially resolved measurement capabilities, we also have access to a larger number of single-point specialized characterization instruments, to study the most interesting points on the combinatorial libraries in more detail.
Automated Data Processing, Analysis, and Visualization
Enormous amounts of data are created by combinatorial synthesis and spatially resolved characterization of the material libraries. So we have developed both local and network-based analysis capabilities to turn these data into knowledge.
- Local computer analysis (project-based custom software package implemented in Igor-PRO and installed on user computers)
- Network accessible database (automated data harvesting, processing and visualization from the deposition and characterization instruments)
Currently, we have data for more than 100,000 individual materials compositions or different processing conditions, reflecting the scale of NREL's Materials Discovery effort.