Infrastructure
Greg Horner, Ph.D. (CTO)
Greg has over 20 years of experience developing novel test and measurement techniques for the solar and semiconductor markets. Prior to founding Tau Science, he held engineering director and staff scientist positions at FEI, KLA-Tencor, and Keithley Instruments. He received a B.A. in Astrogeophysics from Colgate University, an M.S. in Applied Physics from Colorado School of Mines, and a Ph.D. in Electrical Engineering from C.U. Boulder. He performed his graduate research in solar cell and materials characterization at the National Renewable Energy Laboratory, where he focused on growth, processing, characterization and optical modeling of high efficiency multi-junction solar cells and thermophotovoltaics. He has more than 15 patents and 30 technical papers in the field.
Jamie Hudson, Ph.D. (President)
Prior to founding Tau Science, Jamie worked in management roles in the marketing and engineering departments of a Molecular Imaging and FEI Company. Jamie holds a B.S. in Chemistry from U.C., Berkeley, a Ph.D. in Chemistry from Cornell University, and an M.B.A. from the University of Oregon.
Tau Science PixELTM EL/PL System
PixEL™ is a luminescence imaging platform that performs both Photoluminescence and Electroluminescence. The architecture is modeled after the PL/EL system developed and used by Johnston et al at the National Renewable Energy Laboratory in Golden, Colorado. R&D labs that need to measure challenging, weakly luminescent samples will find that this system exhibits industry-leading sensitivity and signal to noise ratio.
For the ultimate in imaging performance <1100nm, a cooled, back-thinned, deep-depletion Silicon camera is used. For samples that exhibit strong luminescence (such as well-passivated Silicon cells), a more economical front-illuminated Silicon camera is offered. For deeper infrared applications [CIGS, CZTS, etc.], InGaAs imagers are also available.
Class 4 lasers may be selected for the most powerful PL illumination source, or lower cost LED’s may be used to reduce system cost when the imaging requirements are less stringent.
An XY stage and macro lens may be added if the user wishes to explore spatial details using a smaller (typically 20x20mm) field of view.
PixEL System Specifications
Base Specifications
- Choice of Silicon or InGaAs cameras:
- Camera Field of View: 100, 125, or 150mm [others on request]
- Camera Macro Lens, optional: 20mm FOV [others on request]
- XY stage, automated, optional: For use with Macro Imaging Lens
- Sample DC Bias for Electroluminescence: ±10 A, ±20 V, 4-Quadrant [others on request]
- Illumination Lasers: Jenoptik, 800nm, air cooled
- Measurement Dwell Time: Configurable. 100ms-10s typical
- AC Power Input: 220-240VAC, 1phase, 10A, 50-60Hz
- User Safety: Automatic Door Interlocks for Laser, Stage
- System Safety: EMO switch
Mechanical Configurations
- Single Cell Imaging
- Full module imaging (High Resolution, 9.3MP Camera is recommended)
- Cell-by-cell imaging of entire module using XY gantry
FlashQEtm - Full Spectrum QE and Reflectance in 1 Second
Tau Science’s innovative FlashQE™ system modernizes one of the most powerful diagnostic tools available to Photovoltaic manufacturers and researchers, Quantum Efficiency. Using a combination of novel optics and analysis techniques (patents pending), FlashQE™ increases measurement throughput by more than one thousand times compared to existing QE systems. Broadband Reflectance, Internal QE, and External QE are measured simultaneously, spanning the range 300-1580nm.
The Mapping QE system includes a measurement chamber, a two-axis stage for automated sample navigation and a feature-rich software control package that allows the user to write and execute measurement recipes. Pass/Fail criteria can be programmed into the recipe to automatically identify out-of-spec wafers based on Rspec, QEext and QEint. A data review package facilitates quick report generation and intuitive navigation of spatially and spectrally resolved maps of conversion efficiency. An optional optical bias is available in both blue and near-IR to study near-surface and bulk trapping.
The QE system can also be integrated in-line for Cell Sorting and Statistical Process Control applications. The system is configurable with one or more factory interface standards (24VDC, Ethernet, Serial) for communication with the handler and communication to a factory host or database. It is available with an automated XY stage (for uniformity maps) or without, for use as a high-throughput fixed-point sampling device.
System Specifications*
-
Base Package
- Wavelength Range: λ=400-1070 nm
- Spot Size: 5mm diameter
- Measurement Dwell Time: 1.3 second per site
- EQE Accuracy: 3%
- Static Precision (3-σ): ≤=1%
- Software UI: Recipe Builder, Recipe Execution, Data Review
- Cell mapping (XY stage): 40 sites/minute [for 5mm moves]
- AC Power Input: 220VAC, 1Φ, 110A, 50-60Hz
-
Options
- Factory Interface: Host control and data upload
- UV Package: Additional wavelengths covering 300-400nm
- Blue (DC) Illumination: λ= 455 nm [Near-surface trap discrimination]
- NIR (DC) Illumination: λ=940nm [Bulk trap discrimination]
- IR Package: Additional wavelengths covering 1090-1580nm
- Custom Spot Size & Shape: Various apertures available
*Specifications are preliminary and subject to change.
