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

Motoshi Nakamura; Keishi Tada; Takumi Kinoshita; Takeru Bessho; Chie Nishiyama; Issei Takenaka; Yoshinori Kimoto; Yuta Higashino; Hiroki Sugimoto; Hiroshi Segawa

doi:10.1016/j.isci.2020.101817

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

iScience. 2020 Nov 18;23(12):101817. doi: 10.1016/j.isci.2020.101817. eCollection 2020 Dec 18.

Authors

Affiliations

¹ Advanced Technology Research Laboratories, Idemitsu Kosan Co.,Ltd., 123-1 Shimokawairi, Atsugi, Kanagawa 243-0206, Japan.
² Research Center for Advanced Science and Technology (RCAST), the University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8904, Japan.
³ Department of General Systems Studies, Graduate School of Arts and Sciences, the University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.

Abstract

The highest theoretical efficiency of double junction solar cells is predicted for architectures with the bottom cell bandgap (E _g ) 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 E _g depending on their elemental composition and depth profile. In this study, various CIGS solar cells with E _g 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-E _g cells as the bottom cell of two-junction solar cells. The four-terminal tandem cell configuration fabricated using a mixed-halide perovskite top cell (E _g = 1.59 eV; stand-alone efficiency = 21.0%) and CIGS bottom cell (E _g = 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.

Keywords: Energy Materials; Inorganic Materials; Materials Application; Materials Science; Optical Materials.