A Sunflower‐Inspired Sun‐Tracking System Directed by an Ionic Liquid Photodetector

Abstract Sunflower‐inspired sun‐tracking systems have been arousing intensive investigations owing to their benefits to improve the efficiency of solar energy collection. Photodetector based on photosensitive semiconductors is a mainstream choice in the sun‐tracking system, which directs solar collectors always facing the sun. However, photosensitive semiconductors to date have usually hidden the disadvantages of environmental pollution after disposal. As for these problems, this work develops a green ionic liquid‐based photodetector, which displays reliable electrical feedback in response to sunlight. This liquid sunlight detector can be readily recycled with less laborious and costly operations. It obeys a light sensing mechanism of photothermal conversion, so it does not involve the problems related to dark current and light saturation. As a practical demonstration, the ionic liquid‐based photodetector is assembled into a sun‐tracking system, which successfully pursues the moving sun in a real time. When such a sun‐tracking system is in tandem with optical fiber concentrator, sunlight can be efficiently collected and transported to desired position.