Light-Induced Effects on the a-Si: H/c-Si Heterointerface

Ravi Vasudevan, Isabella Poli, Dimitrios Deligiannis, Miro Zeman, Arno H.M. Smets

Research output: Contribution to journalArticleScientificpeer-review

1 Citation (Scopus)
32 Downloads (Pure)

Abstract

Light-induced effects on the minority carrier lifetime of silicon heterojunction structures are studied through multiple-exposure photoconductance decay (MEPCD). MEPCD monitors the effect of the measurement flash from a photoconductance decay setup on a sample over thousands of measurements. Varying the microstructure of the intrinsic hydrogenated amorphous silicon (a-Si:H) used for passivation of n-Type crystalline silicon (c-Si) showed that passivating films rich in voids produce light-induced improvement, while denser films result in samples that are susceptible to light-induced degradation. Light-induced degradation is linked to an increase in dangling bond density at the a-Si:H/c-Si interface, while light-induced improvements are linked to charging at the a-Si:H/c-Si interface. Furthermore, doped a-Si:H is added to make samples with an emitter and back surface field (BSF). These doped layers have a significant effect on the light-induced kinetics on minority carrier lifetime. Emitter samples exhibit consistent light-induced improvement, while BSF samples exhibit light-induced degradation. This is explained through negative charging at the BSF and positive charging at the emitter. Full precursors with a BSF and emitter exhibit different kinetics based on which side is being illuminated. This suggests that the light-induced charging at the a-Si:H/c-Si interface can only occur when a-Si:H has sufficient generation.

Original languageEnglish
Article number7786911
Pages (from-to)656-664
Number of pages9
JournalIEEE Journal of Photovoltaics
Volume7
Issue number2
DOIs
Publication statusPublished - 16 Dec 2016

Keywords

  • Hydrogenated amorphous silicon (a-Si:H)
  • light-induced degradation (LID)
  • silicon heterojunction (SHJ)

Fingerprint

Dive into the research topics of 'Light-Induced Effects on the a-Si: H/c-Si Heterointerface'. Together they form a unique fingerprint.

Cite this