Reduction In Optical Reflection At Intermediate Adhesive Layer For Mechanically Stacked Multi Junction Solar Cells
Toshiyuki Sameshima, Yoshihiro Ogawa and Masahiko Hasumi
Volume 3, Issue 5, Page 361-365, Year 2018 | DOI: 10.5185/amp.2018/409
Keywords: Antireflection, optical interference, IGZO. multi-junction solar cell.
Abstract: Reduction of optical reflection loss at the intermediate region is discussed in three mechanical stacked samples: top Si and bottom Ge substrates, top GaAs and bottom Si substrates, and top GaP and bottom Si substrates using an epoxy-type adhesive with a reflective index of 1.47. Transparent conductive Indium gallium zinc oxide (IGZO) layers with a refractive index of 1.85 were used as antireflection layers. IGZO layers were formed on the bottom surface of the top substrate and the top surface of the bottom substrate of the three stacked samples with thicknesses of 188, 130, and 102 nm. The IGZO layers well decreased the optical reflectivity of the stacked samples. The IGZO layers provided high effective optical absorbency Aeff of bottom substrates of 0.925, 0.943, and 0.931, respectively, for light wavelength regions for light in which the top substrates were transparent and the bottom substrates were opaque. High Aeff maintained for the light incident angle between 0 to 50o. Copyright © 2018 VBRI Press.