Flexible fiber/wire-shaped solar cells in progress: properties, materials, and designs

Flexible fiber/wire-shaped solar cells are a kind of photovoltaic cell fabricated on wire-like substrates. Fiber-type devices, including inorganic, organic, dye-sensitized and perovskite solar cells, have made great progress in recent years. In particular, the energy conversion efficiency of fiber dye-sensitized solar cells has increased from <0.5% to >9%. In this review, we have provided very detailed insights into the development of various fiber/wire-shaped solar cells, conventional materials, and innovative designs. Particularly, we focused on the properties of fiber dye-sensitized solar cells, innovations for solar energy harvesting, and the integrated power systems for electrochemical energy conversion and storage. Although recent studies only provided the initial ideas, flexible fiber/wire-shaped solar cells facilitated the breakthrough for novel solar architecture and portable/wearable electronics or e-textiles of the future.