Photovoltaics
Originally developed to provide electrical power for orbiting space
satellites in the 1960s, photovoltaic (PV or solar cell) technology is now
mostly used for grid connected utility power generation. In typical form,
solar cells are packaged in photovoltaic modules and are often connected in
multiples, as solar photovoltaic arrays, to directly convert energy from the
sun into electricity. The term photovoltaic denotes the unbiased operating
mode of a photodiode in which current through the device is entirely due to
absorbed light energy.
First generation PV cells were built using traditional silicon wafer manufacturing technology, which is still dominant for the commercial production of solar cells. Newer alternatives to standard (mono) crystalline silicon photovoltaic modules incorporate thin film technologies, including: cadmium telluride (CdTe), copper indium diselenide (CIS), copper indium disulfide (CuInS2), copper indium gallium selenide (CIGS), amorphous silicon (amorphous Si), and microcrystalline silicon. Other new devices employ photo-electrochemical cells, polymer solar cells, and nanocrystal technology. The latest forth generation devices use composite photovoltaic technology where polymers are mixed with nanoparticles to make a single multi-spectrum layer. For all these technologies, manufacturing approaches range from the traditional FAB model to micro-machined Sliver® cells and continuous printing processes.
X-ray PV Metrology
Whatever the technology or process, Rigaku provides non-destructive, noncontact X-ray based metrology tools for the rapid measurement of a variety of material properties in modern multi-stack PV devices. Whether silicon, glass or metal substrate, Rigaku offers a variety of X-ray diffraction (XRD), small angle X-ray scattering (SAXS), X-ray reflectometry (XRR) and X-ray fluorescence (XRF) tools for either research and development (R&D) or in- FAB process control.
Since the dimensions of X-ray wavelengths are of the same magnitude as the size of nanostructures, XRD and associated techniques are primary tools for the development of new photovoltaic technologies. High-resolution XRD can measure layer thickness, roughness, chemical composition, lattice spacing, relaxation and more. X-ray diffuse scattering is used to determine lateral and transversal correlations, distortions, density, and porosity. In-plane gracing incidence diffraction is employed to study lateral correlations of thinnest organic and inorganic layers as well as depth profiling. Small angle X-ray scattering (SAXS) can determine the size, shape, distribution, orientation, and correlation of nano-particles present in solids or solutions. Finally, XRF can rapidly determine thin-film thickness and composition while XRR can measure layer thickness, roughness, and density without standards.
XRD and SAXS laboratory metrology solutions
- High-power θ/θ XRD system: TTRAX III
- Microdiffraction (μXRD): RAPID II II
- Benchtop XRD: MiniFlex™ II
- Multipurpose XRD, XRR and SAXS: SmartLab®, Ultima IV
- Small angle X-ray scattering (SAXS): S-Max3000, SMT ultra
XRF laboratory metrology solutions
- Low-cost XRF: Primini®, Mini-Z series
- High-performance XRF with mapping: ZSX Primus, ZSX Primus II
- Large sample XRF with mapping: ZSX 400
In-FAB process control
- High throughput XRF/XRD/XRR tool for patterned wafers: MFM65
- Wafer contamination TXRF tool: TXRF-300
- VPD-TXRF wafer contamination tool: TXRF-V300
- In-fab XRF tool: WaferX 300, WDA-3640
Sliver is a registered trademark of Origin Energy Solar, Pty Ltd