Influence of the Oxygen Content on the Optoelectronic Properties of ITO for Silicon Heterojunction Solar Cells
Brahim Aïssa1, Amir A. Abdallah1, Maulid M. Kivambe1, Yahya Zakaria1, Nouar Tabet1, Jean Cattin2, Jan Haschke2, Mathieu Boccard2, Christophe Ballif2
1Qatar Environment and Energy Research Institute, Hamad bin Khalifa University, Qatar Foundation, P.O. Box 34110, Doha, Qatar
/2Photovoltaics and Thin-Film Electronics Laboratory (PV-lab), Institute of Microengineering, Ecole Polytechnique Fédérale de Lausanne, Rue de la Maladière 71B, CH-2002 , Neuchatel, Switzerland

We report on the optoelectronic properties of ITO layers grown by RF sputtering, using different oxygen to total flow ratios [r(O2) = O2/Ar, ranging from 1% to 8%], for silicon heterojunction (SHJ) solar cell application. The depth profiling of the various elements throughout the thicknesses and interfaces of the ITOs and thin films forming the SHJ device was systematically determined by time of flight-secondary ion mass spectrometry (ToF-SIMS). Finally, the photovoltaic performance of the fabricated SHJ cells were evaluated with respect to the r(O2) into the ITO layers. Lower r(O2) was found to yield the best PV performance which is attributed to lower parasitic resistive losses.

Area: Sub-Area 4.4: Passivated Contacts, Carrier Selective Contacts and Hetero-Junction Structures