NASA Scientific and Technical Aerospace Reports
NASA Scientific and Technical Aerospace Reports
NASA Scientific and Technical Aerospace Reports
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specifications automatically. Some experimental results from a fabricated filter are presented.<br />
Author<br />
Switching; Silicon; Computer Aided Design; Capacitors<br />
20060002351 National Renewable Energy Lab., Golden, CO USA<br />
Effect of Nitrogen Concentration on the Performance of Ga1-xInxNyAs1-y Solar Cells<br />
Kurtz, S.; Jonston, S. W.; Geisz, J. F.; Friedman, D. J.; Ptak, A. J.; Feb. 2005; 12 pp.; In English<br />
Report No.(s): DE2005-15016398; NREL/CP-520-37361; No Copyright; Avail.: Department of Energy Information Bridge<br />
A study of Ga1-xInxNyAs1-y solar cells shows that nitrogen degrades the solar cells even for very small nitrogen<br />
concentrations. By comparing the properties of p-on-n <strong>and</strong> n-on-p Ga1-xInxNyAs1-y cells as a function of y, we find that the<br />
n-on-p cells show a more abrupt decrease in the open-circuit voltage <strong>and</strong> greater decrease of the photocurrent. The asymmetry<br />
in the performance of the cells reflects the differences observed for electrons <strong>and</strong> holes in Ga1-xInxNyAs1-y. The electron<br />
mobility is degraded much more than the hole mobility when nitrogen is added to GaAs, implying that the electron diffusion<br />
length should be degraded more than the hole diffusion length. An electron trap (observed by deep-level transient<br />
spectroscopy) affects p-type GaNyAs1-y more than n-type GaNyAs1-y, consistent with the observation that the open-circuit<br />
voltage of n-on-p cells decreases more than that of p-on-n cells. The effect of nitrogen on GaNAs cells is shown to be much<br />
greater than expected for an isoelectronic impurity.<br />
NTIS<br />
Nitrogen; Solar Cells<br />
20060002367 National Renewable Energy Lab., Golden, CO USA<br />
Role of Polycrystalline Thin-Film PV Technologies for Achieving Mid-Term Market-Competitive PV Modules<br />
von Roedern, B.; Zweibel, K.; Ullal, H. S.; Feb. 2005; 14 pp.; In English<br />
Report No.(s): DE2005-15016403; NREL/CP-520-37353; No Copyright; Avail.: Department of Energy Information Bridge<br />
This paper reviews the current commercial status of CuInSe2 alloys (collectively, CIS) <strong>and</strong> CdTe-based photovoltaic (PV)<br />
modules, comparing the performance of commercial products with the results achieved for solar cell <strong>and</strong> prototype module<br />
champions. We provide an update for these PV cell <strong>and</strong> module technologies, <strong>and</strong> also compare CIS <strong>and</strong> CdTe performance<br />
levels to the results achieved by the crystalline Si PV industry. This comparison shows that CIS <strong>and</strong> CdTe module technology<br />
presently offers the best (<strong>and</strong> perhaps only) approach for significantly exceeding the cost/performance levels established by<br />
crystalline Si PV technologies. A semi-empirical methodology is used for comparing ‘champion’ solar cell <strong>and</strong> prototype<br />
module data with performance achieved on manufacturing lines. Using a conservative assumption that thin-film technologies<br />
will eliminate the 40% of PV module costs arising from the Si wafer or ribbon, we estimate the future performance of all<br />
established PV module c<strong>and</strong>idates, <strong>and</strong> conclude that, based on 2004 knowledge about each PV technology, CIS <strong>and</strong> CdTe<br />
should provide cost-competitive advantages over crystalline Si.<br />
NTIS<br />
Modules; Photovoltaic Conversion; Polycrystals; Thin Films<br />
20060002368 National Renewable Energy Lab., Golden, CO USA<br />
Trust But Verity: Procedures to Achieve Accurate Efficiency Measurements for All Photovoltaic Technologies<br />
Emergy, K.; Anderberg, A.; Kiehl, J.; Mack, C.; Feb. 2005; 12 pp.; In English<br />
Report No.(s): DE2005-15016392; NREL/CP-520-36527; No Copyright; Avail.: Department of Energy Information Bridge<br />
The measurement of the photovoltaic (PV) performance with respect to reference conditions requires measuring the<br />
performance with respect to a given tabular reference spectrum, junction temperature, <strong>and</strong> total irradiance. This paper<br />
discusses the procedures implemented by NREL’s PV Cell <strong>and</strong> Module Performance Characterization Group to achieve the<br />
lowest practical uncertainty. This paper describes the process of trusting <strong>and</strong> verifying software, hardware, calibrations,<br />
procedures, <strong>and</strong> results. As an ISO 17025 accredited calibration facility, the quality system that is in place is designed to assure<br />
customers that the results are valid within specified uncertainty limits <strong>and</strong> are traceable. The process of trusting claims but<br />
desiring an independent verification permeates the PV business <strong>and</strong> society.<br />
NTIS<br />
Photovoltaic Conversion; Technologies<br />
20060002398 National Renewable Energy Lab., Golden, CO USA<br />
Lattice-Matched GaNPAs-on-Silicon T<strong>and</strong>em Solar Cells<br />
Geisz, J. F.; Olson, J. M.; Friedman, D. J.; Jones, K. M.; Feb. 2005; 12 pp.; In English<br />
Report No.(s): DE2005-15016402; NREL/CP-520-37349; No Copyright; Avail.: Department of Energy Information Bridge<br />
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