Search documents

Browse topics

Document details

Impact of Surface Morphology and Interfacial Oxide Thickness on Passivation Quality of p+ Polysilicon Passivating Contacts
S. Mack, F. Feldmann, A. Moldovan, M. Lenes, J.M. Luchies, A. Wolf
Passivation, Recombination, LPCVD, Polysilicon, Oxides, Passivated Contact
Silicon Cells
Subtopic: Homojunction Solar Cells
Event: 35th European Photovoltaic Solar Energy Conference and Exhibition
Session: 2AV.2.33
587 - 590
ISBN: 3-936338-50-7
Paper DOI: 10.4229/35thEUPVSEC20182018-2AV.2.33
0,00 EUR
Document(s): paper


The work aims at increasing the knowledge on p-type passivating contacts, especially the impact of the surface morphology and interfacial oxide thickness. Here, p-type passivating contacts are formed by low pressure chemical vapour deposition (LPCVD) of a 240 nm thick boron doped polysilicon layer, which is deposited on top of an in-situ grown interfacial oxide. In the experiment, three different oxide thicknesses are compared on top of five different surface types, i.e. an alkaline textured surface, three subsequently wet-chemically treated alkaline textured surfaces, as well as a planar alkaline saw damage etched surface. After a thermal anneal and SiNx deposition on both sides, which yields symmetrical samples, a contact firing step is used for hydrogenation purposes. The results show a strong correlation between surface morphology and passivation quality, and the highest passivation quality is achieved for saw-damage etched surfaces with implied voltages of up to 737 mV. In addition, the thickness of the interfacial oxide layer has a weaker impact on passivation quality than the morphology.