Integrating perovskite solar cells into a flexible fiber.

Perovskite solar cells have triggered a rapid development of new photovoltaic devices because of high energy conversion efficiencies and their all-solid-state structures. To this end, they are particularly useful for various wearable and portable electronic devices. Perovskite solar cells with a flexible fiber structure were now prepared for the first time by continuously winding an aligned multiwalled carbon nanotube sheet electrode onto a fiber electrode; photoactive perovskite materials were incorporated in between them through a solution process. The fiber-shaped perovskite solar cell exhibits an energy conversion efficiency of 3.3%, which remained stable on bending. The perovskite solar cell fibers may be woven into electronic textiles for large-scale application by well-developed textile technologies.