SiOx Patterned Based Substrates Implemented in Cu(In,Ga)Se2 Ultrathin Solar Cells: Optimum Thickness

• Published in: IEEE journal of photovoltaics 2022, Vol.12 (4), p.954-961
• Main Authors: Oliveira, Kevin, Teixeira, Jennifer P., Chen, Wei-Chao, Lontchi Jioleo, Jackson, Oliveira, Antonio J. N., Caha, Ihsan, Francis, Leonard Deepak, Flandre, Denis, Edoff, Marika, Fernandes, Paulo A., Salome, Pedro M. P.
• Format: Article
• Language: English
• Subjects: Copper indium gallium selenides; Cu(In; Decoupling; electrical simulations; Energy conversion efficiency; Ga)Se<named-content xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" content-type="math" xlink:type="simple"> <inline-formula> <tex-math notation="LaTeX"> _2</tex-math> </inline-formula> </named-content> (CIGS; high-performance substrate; Integrated optics; Lithography; Optical imaging; optical simulations; Optoelectronics; Passivation; Passivity; Performance evaluation; Photovoltaic cells; rear passivation strategy; silicon oxide (SiO<named-content xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" content-type="math" xlink:type="simple"> <inline-formula> <tex-math notation="LaTeX"> _x</tex-math> </inline-formula> </named-content>); Solar cells; Substrates; Thickness; ultrathin
• ISSN: 2156-3381; 2156-3403
• DOI: 10.1109/JPHOTOV.2022.3165764

Interface recombination in sub-μm optoelectronics has a major detrimental impact on devices' performance, showing the need for tailored passivation strategies to reach a technological boost. In this article, SiO x passivation based substrates were developed and integrated into ultrathin Cu(In,Ga)Se 2 (CIGS) solar cells. This article aims to understand the impact of a passivation strategy, which uses several SiO x layer thicknesses (3, 8, and 25 nm) integrated into high-performance substrates (HPS). The experimental study is complemented with 3-D lumerical finite-difference time-domain and 2-D Silvaco ATLAS optical and electrical simulations, respectively, to perform a decoupling of optical and electronic gains, allowing for a deep discussion on the impact of the SiO x layer thickness in the CIGS solar cell performance. This article shows that as the passivation layer thickness increases, a rise in parasitic losses is observed. Hence, a balance between beneficial passivation and optical effects with harmful architectural constraints defines a threshold thickness to attain the best solar cell performance. Analyzing their electrical parameters, the 8-nm novel SiO x based substrate achieved a light to power conversion efficiency value of 13.2%, a 1.3% absolute improvement over the conventional Mo substrate (without SiO x ).