Dokument-ID Dokumenttyp Autoren/innen Persönliche Herausgeber/innen Haupttitel Abstract Auflage Verlagsort Verlag Herausgeber (Institution) Erscheinungsjahr Titel des übergeordneten Werkes Jahrgang/Band ISBN Veranstaltung Veranstaltungsort Beginndatum der Veranstaltung Enddatum der Veranstaltung Ausgabe/Heft Erste Seite Letzte Seite URN DOI Lizenz Datum der Freischaltung OPUS4-24995 Beitrag zu einem Tagungsband Geier, M.; Eberstein, M.; Grießmann, H.; Partsch, U.; Völkel, L.; Böhme, R.; Mann, Guido; Bonse, Jörn; Krüger, Jörg Impact of laser treatment on phosphoric acid coated multicrystalline silicon PV-wafers The selective emitter is a well-known technology for producing highly doped areas under the metallization grid to improve the solar cell performance. In this work, the influence of laser irradiation on phosphoric acid coated multicrystalline silicon PV-wafers on the wafer surface structure, the phosphorous depth distribution and the electrical contact resistance within the laser treated area as well as the electrical series resistance of laserprocessed solar cells was evaluated. Different laser processing settings were tested including pulsed and continuous wave (cw) laser sources (515 nm, 532 nm, 1064 nm wavelength). Complementary numerical simulations using the finite element method (FEM) were conducted to explain the impact of the laser parameters on the melting behavior (melt duration and geometry). It was found that the melt duration is a key parameter for a successful laser Doping process. Our simulations at a laser wavelengths of 515 nm reveal that low-repetition rate (<500 kHz) laser pulses of 300 ns duration generate a melt duration of ~0.35 µs, whereas upon scanning cw-laser radiation at 532 nm prolongates the melt duration by at least one order of magnitude. Experimentally, the widely used ns-laser pulses did not lead to satisfying laser irradiation results. In contrast, cw-laser radiation and scan velocities of less than 2 m/s led to suitable laser doping featuring low electrical resistances in the laser treated areas. 2011 26th European photovoltaic solar energy conference and exhibition (Proceedings) 3-936338-27-2 26th European photovoltaic solar energy conference and exhibition Hamburg, Germany 05.09.2011 08.09.2011 1243 1247 10.4229/26thEUPVSEC2011-2BV.1.7 2016-02-19 OPUS4-24996 Beitrag zu einem Tagungsband Eberstein, M.; Geier, M.; Grießmann, H.; Partsch, U.; Voelkel, L.; Böhme, R.; Pentzien, Simone; Koter, Robert; Mann, Guido; Bonse, Jörn; Krüger, Jörg Towards an industrial laser doping process for the selective emitter using phosphoric acid as dopant Different laser supported approaches have already been realized, proving the great potential of laserdoped selective emitters (LDSE). However, it is challenging to establish a low-cost process by using pulsed laser tools. So far a single-step process only leads to satisfying results utilizing cw-lasers. In this paper we have examined a two-step process to produce laser-doped selective emitters on multicrystalline textured standard silicon photovoltaic wafers (90-Ω/sq-Emitter, SiN-antireflection coating (ARC)). The precise ARC removal by near-infrared fs-laser pulses (30 fs, 800 nm), and the doping of uncoated silicon wafers by ns-laser pulses (8 ns, 532 nm) were systematically investigated. In the fs-experiment, optimum conditions for ARC removal were identified. In the nsexperiments under suitable conditions (melting regime), the phosphorous concentration underneath the wafer surface was significantly increased and the sheet resistance was reduced by nearly a factor of two. Moreover, electrical measurements on fired metallization fingers deposited on the laser processed wafers showed low contact resistances. Hence, wafer conditioning with combined fs-laser- and ns-laser-processes are expected to be a promising technology for producing selective emitters. 2011 26th European photovoltaic solar energy conference and exhibition (Proceedings) 3-936338-27-2 26th European photovoltaic solar energy conference and exhibition Hamburg, Germany 05.09.2011 08.09.2011 1220 1223 10.4229/26thEUPVSEC2011-2BV.1.2 2016-02-19