Effective Surface Texturing of Diamond-Wire-Sawn Multicrystalline Silicon Wafers Via Crystallization of the Native Surface Amorphous Layer

At a Glance

Metadata	Details
Publication Date	2020-11-16
Journal	IEEE Journal of Photovoltaics
Authors	Yujin Jung, Jongwon Ko, Soohyun Bae, Yoonmook Kang, Hae‐Seok Lee
Institutions	Korea University
Citations	4

Abstract

To increase the market shares of multicrystalline silicon (mc-Si) wafers obtained using diamond-wire sawing (DWS), it is necessary to develop efficient and cost-effective texturing methods. Surface texturing processes that increase light absorption are essential for manufacturing high-efficiency solar cells. The smooth surface, phase transformations, and amorphous silicon (a-Si) layer on mc-Si wafers manufactured via DWS hinder the effective texturing under conventional acidic conditions, which are typically used for multiwire slurry sawing (MWSS). To address this issue, this article focused on an efficient texturing process of DWS wafers by adapting a pre-thermal treatment (TT) process. We found that DWS mc-Si wafers could be effectively textured after the TT process by altering the surface roughness through the crystallization of surface amorphous silicon (a-Si) and phase transformation layers. For the DWS mc-Si wafers textured under conventional acidic etching conditions without TT, R w was found to be 31.7%. The altered surface conditions achieved via the proposed TT method facilitate effective texturing on the DWS mc-Si wafer surface. Consequently, a weighted average reflectance (R w ) of 24.5% was obtained, which was comparable to that for MWSS mc-Si wafers subjected to conventional acidic etching (R w = 24.4%). As a result of depositing a SiNx for surface passivation and antireflection coating in solar cell applications, Rw values of 8.1% and 8.3% were obtained for the thermal treated DWS mc-Si wafer and MWSS mc-Si wafer, respectively. The proposed texturing process for DWS mc-Si wafers can easily be applied to industrial inline processes using cost-effective existing acidic etching solutions.

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Original Source

DOI: https://doi.org/10.1109/jphotov.2020.3035122

References

2004 - Texturing industrial multicrystalline silicon solar cells [Crossref]
2020 - A low cost additive-free acid texturing process for large area commercial diamond-wire-sawn multicrystalline silicon solar cells [Crossref]
2013 - Additive for acid texturing of diamond- wire-cutting polycrystalline silicon slices and application method thereof