Hole-Selective Front Contact Stack Enabling 24.1%-Efficient Silicon Heterojunction Solar Cells

• Published in: IEEE journal of photovoltaics Vol. 11; no. 1; pp. 9 - 15
• Main Authors: Boccard, Mathieu, Antognini, Luca, Paratte, Vincent, Haschke, Jan, Truong, Minh, Cattin, Jean, Dreon, Julie, Lin, Wenjie, Senaud, Laurie-Lou, Paviet-Salomon, Bertrand, Nicolay, Sylvain, Despeisse, Matthieu, Ballif, Christophe
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.01.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Absorption; Amorphous silicon; Antireflection coating; carrier-selective contact; Electric contacts; heterojunction; Heterojunctions; Indium oxides; Indium tin oxide; Indium tin oxides; nanocrystalline silicon; Optoelectronics; Oxide coatings; p-layer; passivating contact; Passivation; Photovoltaic cells; Resistance; Silicon; silicon oxide; Solar cells; transparent conductive oxide (TCO); Zirconium oxides
• ISSN: 2156-3381; 2156-3403
• DOI: 10.1109/JPHOTOV.2020.3028262

The window-layer stack limits the efficiency of both-side-contacted silicon heterojunction solar cells. We discuss here the combination of several modifications to this stack to improve its optoelectronic performance. These include the introduction of a nanocrystalline silicon-oxide p-type layer in lieu of the amorphous silicon p-type layer, replacing indium tin oxide with a zirconium-doped indium oxide for the front transparent electrode, capping this layer with a silicon-oxide film and applying a postfabrication electrical biasing treatment. The influence of each of these alterations is discussed as well as their interactions. Combining all of them finally enables the fabrication of a highly transparent and electrically well-performing window-layer stack, leading to a screen-printed silicon heterojunction solar cell with 24.1% efficiency. Paths toward industrialization and further improvements are finally discussed.