Silicon Photonics / Photovoltaics

Multicrystalline Silicon

Multicrystalline Silicon

Multicrystalline silicon wafers are a cost efficient alternative to monocrystalline wafers. However, the fabrication of multicrystalline wafers induces defects that 1. reduce the efficiency of the produced solar cells and  2. lower the mechanical stability of the wafers. The reduced mechanical stability is critical in terms of a targeted reduction of wafer thickness as the multicrystalline solar cells will tend to be increasingly prone to fracture. High internal stress fields occur at defects such as grainboundaries, dislocation clusters, etc..We develop methods to measure these µm-scaled stress fields and investigate the formation mechanisms of these mechanical stress fields. If these formation mechanisms are understood, the wafer producers can be advised on how to avoid such high stresses during the production process.



Thin films on glass
Raman spectroscopy to study internal stresses

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