Perovskite/CIGS Spectral Splitting Double Junction Solar Cell with 28% Power Conversion Efficiency

• Published in: iScience 2020-12, Vol.23 (12), p.101817-101817, Article 101817
• Main Authors: Nakamura, Motoshi, Tada, Keishi, Kinoshita, Takumi, Bessho, Takeru, Nishiyama, Chie, Takenaka, Issei, Kimoto, Yoshinori, Higashino, Yuta, Sugimoto, Hiroki, Segawa, Hiroshi
• Format: Article
• Language: English
• Subjects: Energy Materials; Inorganic Materials; Materials Application; Materials Science; Optical Materials
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2020.101817

The highest theoretical efficiency of double junction solar cells is predicted for architectures with the bottom cell bandgap (Eg) of approximately 0.9–1.0 eV, which is lower than that of a typical Si cell (1.1 eV). Cu(In,Ga)(Se,S)2 (CIGS) solar cells exhibit a tunable Eg depending on their elemental composition and depth profile. In this study, various CIGS solar cells with Eg ranging from 1.02 to 1.14 eV are prepared and a spectrum splitting system is used to experimentally demonstrate the effect of using lower-Eg cells as the bottom cell of two-junction solar cells. The four-terminal tandem cell configuration fabricated using a mixed-halide perovskite top cell (Eg = 1.59 eV; stand-alone efficiency = 21.0%) and CIGS bottom cell (Eg = 1.02 eV; stand-alone efficiency = 21.5%) with a 775-nm spectral splitting mirror exhibits an efficiency of 28.0% at the aperture area of 1 cm2. [Display omitted] •CIGS bottom solar cells with Eg ranging from 1.02 to 1.14 eV are prepared•The lower the Eg of CIGS bottom cell, the higher PCE of PVK/CIGS tandem solar cell•PCE of 28% was demonstrated in a 1 cm2-sized PVK/CIGS 4-Terminal solar cell•The result can be utilized to design better tandem solar cell in the future Inorganic Materials; Optical Materials; Materials Science; Materials Application; Energy Materials