Schedule 1 1:30 PM - 3:00 PM [ICNN-P-19] Natural β-carotene as electron donor materials in see-through organic solar cells *Takayuki Uchiyama1, Takashi Sano1, Varun Vohra1, Yoshiko Okada-Shudo1 (1. The Univ. of Electro-Commun.)