Intermediate Layer Development for Laser-Crystallized Thin-Film Silicon Solar Cells on Glass

Jonathon Dore,Sergey Varlamov,Martin A Green

doi:10.1109/jphotov.2014.2361033

Abstract

The intermediate layer (IL) between the glass and silicon plays an important role in laser-crystallized thin-film silicon solar cells. SiO X , SiN X , and SiC X deposited by RF sputtering or plasma-enhanced chemical vapor deposition, either as single layers or in stacks, have been tested as ILs with regard to silicon wettability and silicon crystal quality and the effect of hydrogen passivation. SiC X is the best wetting layer, allowing a larger laser crystallization process window than SiO X or SiN X . SiN X layers are limited by pinholing, which increases in severity with laser fluence. SiO X ILs result in lower silicon grain-boundary density compared with SiC x -based layers and to SiN X -based layers. Hydrogen passivation of laser-crystallized silicon on single layer SiO X has no impact on V OC , while an improvement of around 60 mV is found for samples on SiO x /SiN x /SiO x stacks. Diffusion of dopants from the IL are found to create a uniformly doped absorber with no evidence of a front-surface field.

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