Recently, the researchers at KRICT reported a record 18.9% perovskite solar cell realized by compositional engineering. Please read the following link：

Compositional engineering of perovskite materials for high-performance solar cell

Nam Joong Jeon, Jun Hong Noh, Woon Seok Yang, Young Chan Kim, Seungchan Ryu, Jangwon Seo & Sang Il Seok, Nature 2015

The story about the record efficiency Nature paper

Perovskite Solar Cell Bests Bugbears, Reaches Record Efficiency