Capabilities

Capabilities

Secondary Ion Mass Spectrometry (SIMS)

Laboratory

National Renewable Energy Laboratory (NREL)

Capability Expert

Steven Harvey

Class

Benchmarking
Characterization

Node Readiness Category

2: High-Temperature Electrolysis (HTE)
2: Low-Temperature Electrolysis (LTE)
2: Photoelectrochemical (PEC)
2: Solar Thermochemical (STCH)

Description

Secondary ion mass spectrometry (SIMS) is a powerful analytical technique useful for measurements of organic surfaces, dopants and impurities in solids, and diffusion across interfaces.
Time of Flight SIMS (TOF-SIMS) provides surface spectroscopy of both inorganic and organic materials, and is capable of detection limits in the sub-ppm range. High-lateral-resolution (>80 nm) chemical imaging is also possible; recent TOF-SIMS work at NREL has focused on understanding grain-boundary segregation effects in materials such as thin-film polycrystalline CdTe via high-resolution 3-D tomography.
Dynamic SIMS excels at measuring dopant concentrations at extremely low levels in solid materials. Dopants are routinely measured in the parts-per-billion (ppb) and sub-ppb levels.

Capability Bounds‎

The largest sample which can fit into the NREL system is 3x5 inches in size; the smallest samples we can measure are a few square millimeters. While TOF-SIMS can investigate organics and organic coatings, dynamic SIMS is only capable of investigating inorganic materials. Materials must be stable in vacuum at room temperature.

Unique Aspects‎

The NREL TOF-SIMS is a near state-of-the art ION-TOF TOF-SIMS V. The primary operator at NREL has extensive and varied experience utilizing TOF-SIMS to investigate a variety of materials including oxides, organics, and semiconductors. The NREL dynamic SIMS is a CAMECA 7F spectrometer capable of routinely measuring dopants in the ppb concentration range.

Availability‎

These capabilities are available for use within the HydroGEN consortium effort with no significant restrictions. NRELs staff are available to perform measurements, and can also host visitors to NREL.

Benefit‎

TOF-SIMS is an extremely versatile technique capable of non-destructive investigation of surface coatings, as well as high-resolution imaging and tomography. Dynamic SIMS can measure dopants with sensitivity unmatched by most other methods.

Images

Figure 1. A. 50x50µm image of the Ni signal in a composite NiO/Ba(1-x)YxCe(1-Y)ZryO3. B. 50x50µm image of the Ba signal in a composite NiO/Ba(1-x)YxCe(1-Y)ZryO3. C. 3-D rendering of both the Ba (blue) and Ni (yellow)signal in a composite NiO/Ba(1-x)YxCe(1-Y)ZryO3.

Figure 2. 3-D rendering of phosphorous dopant distribution in polycrystalline CdTe. High signal is red, at the grain-boundaries, and low signal is black, in the grain interiors.

Figure 3. Top: Structural rendering of the hybrid organic-inorganic perovskite photovoltaic material. Bottom: A series of regions from the TOF-SIMS mass spectra showing peaks related to the hybrid organic-inorganic perovskite material.

Figure 4. A. Standard depth profile of a completed perovskite photovoltaic device. B. 3-D tomography rendering of a completed perovskite PV device.

References‎

Colegrove, E., S. P. Harvey, et al. (2016). "Phosphorus Diffusion Mechanisms and Deep Incorporation in Polycrystalline and Single-Crystalline CdTe." Physical Review Applied 5(5): 054014; Harvey, S. P., G. Teeter, et al. (2015). Progress in Photovoltaics 23(7): 838-846.
http://www.nrel.gov/materials-science/interfacial-surface-science.html