Hot spots in multicrystalline silicon solar cells

Avalanche breakdown due to etch pits

authored by

J. Bauer, J. M. Wagner, A. Lotnyk, H. Blumtritt, B. Lim, J. Schmidt, O. Breitenstein

Abstract

Multicrystalline silicon solar cells typically show hard breakdown beginning from about -13 V bias, which leads to the well-known hot-spot problem. Using special lock-in thermography techniques, hard breakdown has been found to occur in regions of avalanche multiplication. A systematic study of these regions by various electron microscopy techniques has shown that the avalanche breakdown occurs at cone-shaped holes, located at dislocations and caused by acidic texture etch. At their bottom, these etch pits lead to a strongly curved p-n junction exhibiting an electrostatic tip effect which quantitatively explains the field enhancement needed for enabling avalanche breakdown.

External Organisation(s)

Max Planck Institute of Microstructure Physics
Institute for Solar Energy Research (ISFH)

Type

Article

Journal

Physica Status Solidi - Rapid Research Letters

Volume

3

Pages

40-42

No. of pages

3

ISSN

1862-6254

Publication date

2009

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

General Materials Science, Condensed Matter Physics

Electronic version(s)

https://doi.org/10.1002/pssr.200802250 (Access: Unknown)