Search documents

Browse topics

Document details

Amorphous Silicon Carbide Hetero-Emitters for High Efficiency Silicon Solar Cells
S. Janz, J. Ziegler, D. Pysch, D. Suwito, S.W. Glunz
Heterojunction, Silicon Carbide, High Efficiency
Wafer-Based Silicon Solar Cells and Materials Technology
Subtopic: Mono- and Multicrystalline Silicon Cells and Materials, Processing Technology of
Event: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain
Session: 2CV.5.43
1720 - 1723
ISBN: 3-936338-24-8
Paper DOI: 10.4229/23rdEUPVSEC2008-2CV.5.43
0,00 EUR
Document(s): paper


We investigated different amorphous SixC1-x:H layers for their applicability as hetero-emitter materials. The deposition with Plasma Enhanced Chemical Vapour Deposition (PECVD) in a preliminary industrial stage plasma reactor was done without any wet-chemical pre-cleaning directly before the deposition. In a first step the single layers were characterised optically with Spectral Ellipsometry (SE) which showed an enhanced transparency of a-SixC1-x:H layers with a very low carbon content below 10 % compared to a-Si:H. On both sides passivated Si float zone wafers we measured minority carrier lifetimes with the Quasi Steady-State Photoconductance (QSS-PC) method which showed excellent passivation performance for 70 nm thick layers and a detrimental performance loss for thicknesses below 10 nm. With the Constant Photocurrent Method (CPM) we found a significant increase of the Urbach energy when incorporating phosphorous into the layer network. The solar cell had a hetero-junction on the front-side and a passivated rear-side (SiO2) with local contacts (PERC). The first cell batches were strongly influenced by technological problems such as material inhomogeneities over the cell area, contaminations on the surface and a poor grid finger/ITO adhesion behaviour. Nevertheless, we could achieve an excellent open circuit voltage of 674 mV.