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Fabrication and characterization of a co-planar detector in diamond for low energy single ion implantation

Applied Physics Letters

Abraham, John B.; Pacheco, Jose L.; Aguirre, Brandon A.; Vizkelethy, Gyorgy V.; Bielejec, Edward S.

We demonstrate low energy single ion detection using a co-planar detector fabricated on a diamond substrate and characterized by ion beam induced charge collection. Histograms are taken with low fluence ion pulses illustrating quantized ion detection down to a single ion with a signal-to-noise ratio of approximately 10. We anticipate that this detection technique can serve as a basis to optimize the yield of single color centers in diamond. In conclusion, the ability to count ions into a diamond substrate is expected to reduce the uncertainty in the yield of color center formation by removing Poisson statistics from the implantation process.

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TYPE Journal Article YEAR 2016
DOIOSTI

Next Generation Photovoltaic Technologies For High-Performance Remote Power Generation (Final Report)

Lentine, Anthony L.; Nielson, Greg N.; Riley, Daniel R.; Okandan, M.; Sweatt, W.C.; Jared, Bradley H.; Resnick, Paul J.; Kim, B.; Kratochvil, Jay; Anderson, B.J.; Cruz-Campa, J.L.; Gupta, Vipin P.; Tauke-Pedretti, Anna; Cederberg, J.G.; Paap, Scott M.; Sanchez, Carlos A.; Nordquist, Christopher N.; Saavedra, Michael P.; Ballance, Mark H.; Nguyen, J.; Alford, Charles A.; Nelson, John S.; Lavin, Judith M.; Clews, P.; Pluym, Tammy P.; Wierer, J.; Wang, George T.; Biefeld, Robert M.; Luk, Ting S.; Brener, Igal B.; Granata, J.; Aguirre, Brandon A.; Haney, Mike; Agrawal, Gautam; Gu, Tian

A unique, micro-scale architecture is proposed to create a novel hybrid concentrated photovoltaic system. Micro-scale (sub-millimeter wide), multi-junction cells are attached to a large-area silicon cell backplane (several inches wide) that can optimally collect both direct and diffuse light. By using multi- junction III-V cells, we can get the highest possible efficiency of the direct light input. In addition, by collecting the diffuse light in the large-area silicon cell, we can produce power on cloudy days when the concentrating cells would have minimal output. Through the use of micro-scale cells and lenses, the overall assembly will provide higher efficiency than conventional concentrators and flat plates, while keeping the form factor of a flat plate module. This report describes the hybrid concept, the design of a prototype, including the PV cells and optics, and the experimental results.

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TYPE SAND Report YEAR 2016
DOIOSTI

Mapping photovoltaic performance with nanoscale resolution

Progress in Photovoltaics: Research and Applications

Cruz-Campa, Jose L.; Aguirre, Brandon A.; Kutes, Yasemin; Bosse, James L.; Zubia, David; Huey, Bryan D.

Photo-conductive AFM spectroscopy ('pcAFMs') is proposed as a high-resolution approach for investigating nanostructured photovoltaics, uniquely providing nanoscale maps of photovoltaic (PV) performance parameters such as the short circuit current, open circuit voltage, maximum power, or fill factor. The method is demonstrated with a stack of 21 images acquired during in situ illumination of micropatterned polycrystalline CdTe/CdS, providing more than 42 000 I/V curves spatially separated by ~5 nm. For these CdTe/CdS microcells, the calculated photoconduction ranges from 0 to 700 picoSiemens (pS) upon illumination with ~1.6 suns, depending on location and biasing conditions. Mean short circuit currents of 2 pA, maximum powers of 0.5 pW, and fill factors of 30% are determined. The mean voltage at which the detected photocurrent is zero is determined to be 0.7 V. Significantly, enhancements and reductions in these more commonly macroscopic PV performance metrics are observed to correlate with certain grains and grain boundaries, and are confirmed to be independent of topography. These results demonstrate the benefits of nanoscale resolved PV functional measurements, reiterate the importance of microstructural control down to the nanoscale for 'PV devices, and provide a widely applicable new approach for directly investigating PV materials.

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TYPE Journal Article YEAR 2016
DOIOSTIScopus
Results 26–50 of 51
Results 26–50 of 51