Autodiffusion

A novel method for emitter formation in crystalline silicon thin-film solar cells

verfasst von
A. Wolf, B. Terheiden, R. Brendel
Abstract

The in situ formation of an emitter in monocrystalline silicon thin-film solar cells by solid-state diffusion of dopants from the growth substrate during epitaxy is demonstrated. This approach, that we denote autodiffusion, combines the epitaxy and the diffusion into one single process. Layer-transfer with porous silicon (PSI process) is used to fabricate n-type silicon thin-film solar cells. The cells feature a boron emitter on the cell rear side that is formed by autodiffusion. The sheet resistance of this autodiffused emitter is 330 Ω/□- An independently confirmed conversion efficiency of (14.5 ± 0.4)% with a high short circuit current density of (33.3 ± 0.8) mA/cm2 is achieved for a 2 × 2 cm2 large cell with a thickness of (24 ± 1) μm. Transferred n-type silicon thin films made from the same run as the cells show effective carrier lifetimes exceeding 13 μs. From these samples a bulk diffusion ength L > 111 μm is deduced. Amorphous silicon is used to passivate the rear surface of these samples after the layer-transfer resulting in a surface recombination velocity lower than 38cm/s.

Externe Organisation(en)
Institut für Solarenergieforschung GmbH (ISFH)
Typ
Artikel
Journal
Progress in Photovoltaics: Research and Applications
Band
15
Seiten
199-210
Anzahl der Seiten
12
ISSN
1062-7995
Publikationsdatum
05.2007
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Elektronische, optische und magnetische Materialien, Erneuerbare Energien, Nachhaltigkeit und Umwelt, Physik der kondensierten Materie, Elektrotechnik und Elektronik
Ziele für nachhaltige Entwicklung
SDG 7 – Erschwingliche und saubere Energie
Elektronische Version(en)
https://doi.org/10.1002/pip.727 (Zugang: Geschlossen)