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Title
Verfahren zur lichtinduzierten galvanischen Pulsabscheidung zur Ausbildung einer Saatschicht fuer einen Metallkontakt einer Solarzelle und zur nachfolgenden Verstaerkung dieser Saatschicht bzw. dieses Metallkontakts sowie Anordnung zur Durchfuehrung des Verfahrens
Date Issued
2009
Author(s)
Radtke, V.
Bay, N.
Aleman, M.
Patent No
102009051688
Abstract
(A1) Die vorliegende Erfindung beschreibt ein lichtinduziertes galvanisches Abscheidungsverfahren, wobei sowohl die Potentialdifferenz zwischen einem ersten Metallkontakt und einer Hilfselektrode gemaess einer vordefinierten Spannungs-Zeit-Charakteristik zeitabhaengig variiert wird, als auch eine Lichteinstrahlung auf eine Solarzelle gemaess einer Lichtbestrahlungs-Zeit-Charakteristik.
DE 102009051688 A1 UPAB: 20110511 NOVELTY - The light inducing galvanic deposition process for galvanic formation of a second metal contact and for galvanic strengthening of the second metal contact in a solar cell having a first metal contact, comprises subjecting the solar cell with its auxiliary electrode serving the metal contact and as anode section-wisely in electrolytic bath (6), and producing a potential difference between the first metal contact of the solar cell and the auxiliary electrode so that the first metal contact lies on a negative potential related to the auxiliary electrode. DETAILED DESCRIPTION - The light inducing galvanic deposition process for galvanic formation of a second metal contact and for galvanic strengthening of the second metal contact in a solar cell having a first metal contact, comprises subjecting the solar cell with its auxiliary electrode serving the metal contact and as anode section-wisely in electrolytic bath (6), and producing a potential difference between the first metal contact of the solar cell and the auxiliary electrode so that the first metal contact lies on a negative potential related to the auxiliary electrode, and the solar cell is irradiated with light (5). The potential difference between the first metal contact and the auxiliary electrode is varied to pre-determined first characteristics indicated as voltage-time-characteristics in time dependent manner, and/or the time-dependent variations are produced corresponding to the current density change. The light irradiation is varied on the solar cell in accordance with a pre-determined second characteristics indicated as light radiation-time-characteristics in time-dependent manner, and/or the time-dependent variation is produced corresponding to the current density change. The time-dependent variation and/or the current density change are carried out in accordance with the first characteristics synchronized with the time-dependent variation and/or current density change corresponding to the variation according to the second characteristics. The first characteristics and the second characteristics are formed so that a light irradiation is periodically carried out on the solar cell in defined time interval and potential difference between the first metal contact and the auxiliary electrode. A passivation layer of the solar cell applied on a side opposite to the first metal contact of the solar cell is areawisely opened before the solar cell is applied in its first metal contacts in the electrolytic bath. The first characteristics and/or the second characteristics, periodical variation and/or pulse sequence are formed to produce a corresponding current density change. The first pulse sequence of the first characteristics is laterally synchronized with a second pulse sequence of the second characteristics. A time period lies between the pulse sequences without variation of the first characteristics and/or the second characteristics and/or corresponding current density change and/or through anodic pulse to begin a pulse sequence of the first and/or the second characteristics, and/or through a pulse sequence of the first and/or the second characteristics with individual pulse of different- time duration, size, polarity, time interval between the pulses, and/or through overlapping of pulses of different size in a pulse sequence of the first and/or the second characteristics. A photovoltaic effect is produced by the potential difference according to first characteristics and the light radiation according to second characteristics so that a current in the solar cell is induced in such a way that a second metal contact of the solar cell is formed in the form of a seed layer with a thickness of 50-500 nm as cathode and is thickened through further maintenance of the potential difference according to the first characteristics and the light radiation according to the second characteristics. The side of the solar cell opposite to the first metal contact of the solar cell is irradiated according to the second characteristics with light. The first metal contact is a part section of the backside contact of the solar cell and/or an electric contact of the solar cell arranged on a p-doped side of the solar cell, and/or the second metal contact is a part section of a front side contact of the solar cell, an electric contact arranged on the light radiation-turning side of the solar cell, and/or the electric contact of the solar cell arranged on an n-doped side of the solar cell. The potential difference between the first metal contact and the auxiliary electrode is produced over a voltage source connected with a function generator (3) switched between the first metal contact and the auxiliary electrode formed integrated with the function generator. The potential difference produced from the voltage source by function generator is varies in time-dependent manner, and/or the potential difference between the first metal contact and the auxiliary electrode is varied in which different voltage sources are turned between the first metal contact and the auxiliary electrode. The electrolytic bath consists of nickel ion, cobalt ion and/or tungsten iron, and/or the light radiation is varied on the solar cell in time-dependent manner in which first and second light intensity is radiated on the solar cell during the time interval. The intensity change is repeatedly and/or periodically carried out. The solar cell is tempered before, during and/or after the variation of the potential difference according to the first characteristics and the variation of the light beam according to the second characteristics, where the temperature of the tempering is 150-600 degrees C and the duration of the tempering is 10-20 min. An INDEPENDENT CLAIM is included for an arrangement for light inducing galvanic deposition process. USE - Light inducing galvanic deposition process useful for galvanic formation of a second metal contact and for galvanic strengthening of the second metal contact in a solar cell. ADVANTAGE - The light inducing galvanic deposition process increases the efficiency of the solar cell with better liability and electrical conductivity.
Language
de
Patenprio
DE 102009051688 A: 20091023