Broadband triple-layer SiO x /SiO x N y /SiN x antireflective coatings in textured crystalline silicon solar cells.

Abstract: The purpose of this study is to reduce textured crystalline silicon (TCS) substrate surface-reflectivity over a wide spectral range (300–1100nm), to improve the step coverage of the textured structure, and to shift the minimal value of reflection from the unabsorbed region to the absorbed region. The TCS solar-cell interface between air and silicon was added to a SiO x /SiO x N y /SiN x triple-layer anti-reflective coatings (TLARCs) structure using the plasma-enhanced chemical vapor deposition (PECVD) growth method. This paper presents theoretical and practical discussions, as well as the experimental results of fabricating the films and devices. The average reflection of the SiO x /SiO x N y /SiN x TLARs reduced to 2.01% (300–1100nm). The minimal value of reflection was shifted from 1370nm (unabsorbed region) to 968nm (absorbed region). The SEM images show effective step coverage. In comparison to the untreated TCS solar cells, applying the experimental SiO x /SiO x N y /SiN x TLARCs to conventional TCS solar cells improved the short-circuit current density (J sc ) by 7.78%, and solar-cell efficiency by 10.95%. This study demonstrates that the SiO x /SiO x N y /SiN x TLARCs structure provides antireflective properties over a broad range of visible and near-infrared light wavelengths. An effective step coverage and minimal value of reflection from unabsorbed region shift to the absorbed region is demonstrated. [Copyright &y& Elsevier]