Influence of laser wavelength on Laser-Fired contacts for crystalline silicon solar cells

In the Laser-Fired Contact (LFC) process, a laser beam fires a metallic layer through a dielectric passivating layer into the silicon wafer to form an electrical contact with the silicon bulk [1]. This laser technique is an interesting alternative for the fabrication of both laboratory and industrial scale high efficiency passivated emitter and rear cell (PERC). One of the principal characteristics of this promising technique is the capability to reduce the recombination losses at the rear surface in crystalline silicon solar cells. Therefore, it is crucial to optimize LFC because this process is one of the most promising concepts to produce rear side point contacts at process speeds compatible with the final industrial application. In that sense, this work investigates the optimization of LFC processing to improve the back contact in silicon solar cells using fully commercial solid state lasers with pulse width in the ns range, thus studying the influence of the wavelength using the three first harmonics (corresponding to wavelengths of 1064 nm, 532 nm and 355 nm). Previous studies of our group focused their attention in other processing parameters as laser fluence, number of pulses, passivating material [2, 3] thickness of the rear metallic contact [4], etc. In addition, the present work completes the parametric optimization by assessing the influence of the laser wavelength on the contact property. In particular we report results on the morphology and electrical behaviour of samples specifically designed to assess the quality of the process. In order to study the influence of the laser wavelength on the contact feature we used as figure of merit the specific contact resistance. In all processes the best results have been obtained using green (532 nm) and UV (355 nm), with excellent values for this magnitude far below 1 mΩcm2.

Performance metrics for small-signal stability assessment of DC-distributed power-system-architecture comparisons

The objective of this paper is to provide performance metrics for small-signal stability assessment of a given system architecture. The stability margins are stated utilizing a concept of maximum peak criteria (MPC) derived from the behavior of an impedance-based sensitivity function. For each minor-loop gain defined at every system interface, a single number to state the robustness of stability is provided based on the computed maximum value of the corresponding sensitivity function. In order to compare various power-architecture solutions in terms of stability, a parameter providing an overall measure of the whole system stability is required. The selected figure of merit is geometric average of each maximum peak value within the system. It provides a meaningful metrics for system comparisons: the best system in terms of robust stability is the one that minimizes this index. In addition, the largest peak value within the system interfaces is given thus detecting the weakest point of the system in terms of robustness.

Systematic Method to Assess Small-Signal Stability of DC-Distributed Power-System-Architecture

The objective of this paper is to present a simplified method to analyze small-signal stability of a power system and provide performance metrics for stability assessment of a given power-system-architecture. The stability margins are stated utilizing a concept of maximum peak criteria (MPC), derived from the behavior of an impedance-based sensitivity function that provides a single number to state the robustness of the stability of a well-defined minor-loop gain. For each minor-loop gain, defined at every system interface, the robustness of the stability is provided as a maximum value of the corresponding sensitivity function. Typically power systems comprise of various interfaces and, therefore, in order to compare different architecture solutions in terms of stability, a single number providing an overall measure of the whole system stability is required. The selected figure of merit is geometric average of each maximum peak value within the system, combined with the worst case value of system interfaces.

In search of merit : hiring entry-level federal employees : a report to the President and the Congress of the United States /

Mode of access: Internet.

Figure of Lu Dongbin

Metalwork, Chinese, Ming; H: 10 3/64 in.; cast bronze

Figure of a Mythical Lion

Metalwork, Chinese, Ming; L: 3 35/64 in.; gilt bronze inlaid with precious stones

A history of the mathematical theories of attraction and the figure of the earth from the time of Newton to that of Laplace.

Available on demand as hard copy or computer file from Cornell University Library.

The figure of the earth, : determined from observations made by order of the French King, at the Polar circle: /

Head- and tail-pieces, initials.

A treatise on the Diatomaceae, containing introductory remarks on the structure, life history, collection, cultivation and preparation of diatoms, and a description and figure typical of every known genus, as well as a description and figure of every species found in the North Sea and countries bordering it, including Great Britain, Belgium, &c.

Reprint of the 1896 ed.

An essay on the credibility of Swedenborg; in which his claims as the announcer of the dispensation mentioned in prophecy under the figure of the New Jerusalem, are briefly considered and defended.

Mode of access: Internet.

An account of experiments to determine the figure of the earth : by means of the pendulum vibrating seconds in different latitudes, as well as on various other subjects of philosophical inquiry /

"Printed at the expense of the Board of Longitude."

Mathematical tracts on the lunar and planetary theories, the figure of the earth, precession and nutation, the calculus of variations, and the undulatory theory of optics. Designed for the use of students in the university.

Mode of access: Internet.

The law of the offerings in Leviticus I-VII, considered as the appointed figure of the various aspects of the offering of the body of Jesus Christ.

Mode of access: Internet.

Directory of U.S. Register of Merit sires and dams qualifying under the National Poultry Improvement Plan, 1941-42 trap-nest record year /

"November 1943."

Directory of U.S. Register of Merit sires and dams qualifying under the National Poultry Improvement Plan, 1942-43 /

"December 1944."