Analysis of lateral transport through the inversion layer in amorphous silicon/crystalline silicon heterojunction solar cells

Miha Filipič, Zachary Holman, Franc Smole, Stefaan De Wolf, Christophe Ballif, Marko Topič

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

In amorphous/crystalline silicon heterojunction solar cells, an inversion layer is present at the front interface. By combining numerical simulations and experiments, we examine the contribution of the inversion layer to lateral transport and assess whether this layer can be exploited to replace the front transparent conductive oxide (TCO) in devices. For this, heterojunction solar cells of different areas (2 × 2, 4 × 4, and 6 × 6 mm 2) with and without TCO layers on the front side were prepared. Laser-beam-induced current measurements are compared with simulation results from the ASPIN2 semiconductor simulator. Current collection is constant across millimeter distances for cells with TCO; however, carriers traveling more than a few hundred microns in cells without TCO recombine before they can be collected. Simulations show that increasing the valence band offset increases the concentration of holes under the surface of n-type crystalline silicon, which increases the conductivity of the inversion layer. Unfortunately, this also impedes transport across the barrier to the emitter. We conclude that the lateral conductivity of the inversion layer may not suffice to fully replace the front TCO in heterojunction devices.

Original languageEnglish (US)
Article number074504
JournalJournal of Applied Physics
Volume114
Issue number7
DOIs
StatePublished - Aug 21 2013
Externally publishedYes

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amorphous silicon
heterojunctions
solar cells
inversions
silicon
oxides
heterojunction devices
conductivity
simulation
cells
simulators
emitters
laser beams
valence

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Analysis of lateral transport through the inversion layer in amorphous silicon/crystalline silicon heterojunction solar cells. / Filipič, Miha; Holman, Zachary; Smole, Franc; De Wolf, Stefaan; Ballif, Christophe; Topič, Marko.

In: Journal of Applied Physics, Vol. 114, No. 7, 074504, 21.08.2013.

Research output: Contribution to journalArticle

Filipič, Miha ; Holman, Zachary ; Smole, Franc ; De Wolf, Stefaan ; Ballif, Christophe ; Topič, Marko. / Analysis of lateral transport through the inversion layer in amorphous silicon/crystalline silicon heterojunction solar cells. In: Journal of Applied Physics. 2013 ; Vol. 114, No. 7.
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