Local rear contacts to silicon solar cells by in-line high-rate evaporation of aluminum

verfasst von

Christoph Mader, Jens Müller, Stefan Eidelloth, Rolf Brendel

Abstract

We contact p-type wafers and boron-diffused layers by laser ablation of a passivating aluminum oxide and silicon nitride stack and subsequent in-line high-rate evaporation of aluminum. We measure saturation current densities at the base contacts of 2.5×10 ⁶-1.9×10 ⁷ fA/cm ² for base resistivities of 0.5-3.8 Ω cm and 491-905 fA/cm ² for the contacts to boron-diffused layers of sheet resistances of 23-86 Ω/sq. The contact resistivity of Al layers to p-type silicon with surface doping densities of 4×10 ¹⁵-3×10 ¹⁹ cm ^-3 is in the range of 4-0.1 mΩ cm ², respectively. The measured contact properties allow for the fabrication of highly efficient 'passivated emitter and rear cells' (PERC) and 'passivated emitter and rear totally diffused cells' (PERT). Numerical simulations show that evaporated rear contacts in combination with screen printed contacts at the front allow for energy conversion efficiencies of 20.6% and of 21.1%, for PERC and PERT cells, respectively. The simulated free energy losses show that such cells are not limited by the in-line evaporated point contacts on the rear side.

Organisationseinheit(en)

Institut für Festkörperphysik

Externe Organisation(en)

Institut für Solarenergieforschung GmbH (ISFH)

Typ

Artikel

Journal

Solar Energy Materials and Solar Cells

Band

107

Seiten

272-282

Anzahl der Seiten

11

ISSN

0927-0248

Publikationsdatum

12.2012

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Elektronische, optische und magnetische Materialien, Erneuerbare Energien, Nachhaltigkeit und Umwelt, Oberflächen, Beschichtungen und Folien

Ziele für nachhaltige Entwicklung

SDG 7 – Erschwingliche und saubere Energie

Elektronische Version(en)

https://doi.org/10.1016/j.solmat.2012.06.047 (Zugang: Geschlossen)