Structural study on (Al)InGaP single-junction solar cell for performance improvement of triple-junction solar cells

Morioka, Chiharu*; Imaizumi, Mitsuru*; Sugimoto, Hiroki*; Sato, Shinichiro; Oshima, Takeshi; Tajima, Michio*

Proceedings of 17th International Photovoltaic Science and Engineering Conference (PVSEC-17) (CD-ROM), p.504 - 505, 2007/12

Radiation resistance of (Al)InGaP solar cells was examined in this study. The epitaxial structure, such as aluminum contents or carrier concentration (CC) in the base layer, is varied, whereas the base layer thickness is maintained at 1 m. The cells are irradiated with 3 MeV protons up to the fluence of cm. Remaining factors of short-circuit current and open-circuit voltage show no significant difference between AlInGaP and InGaP cells. The graded CC structure in the base layer is ineffective to improve radiation resistance in the case of (Al)InGaP cells with a thick base layer, which implies that radiation degradation is not primarily attributable to the decrease in minority-carrier diffusion length.