Self‐Powered Organic Electrochemical Transistors with Stable, Light‐Intensity Independent Operation Enabled by Carbon‐Based Perovskite Solar Cells

Abstract Wearable sensors and electronics for health and environment monitoring are mostly powered by batteries or external power supply, which requires frequent charging or bulky connecting wires. Self‐powered wearable electronic devices realized by integrating with solar cells are becoming increasingly popular due to their ability to supply continuous and long‐term energy to power wearable devices. However, most of the solar cells are vulnerable to significant power losses with decreasing light intensity in indoor environment, leading to an errant device operation. Therefore, stable autonomous energy in a reliable and repeatable way without affecting their operation regime is critical to attaining accurate detection behaviours of electronic devices. Herein, we demonstrate, for the first time, a self‐powered ion‐sensing organic electrochemical transistor (OECT) using carbon electrode‐based perovskite solar cells (CPSCs), which exhibits highly stable device operation and independent of the incident light intensity. The organic electrochemical transistors (OECTs) powered by CPSCs maintained a constant transconductance ( g m ) of ≈60.50 ± 1.44 µS at light intensities ranging from 100 to 0.13 mW cm −2 . Moreover, this self‐powered integrated system showed good sodium ion sensitivity of −69.77 mV decade −1 , thereby highlighting its potential for use in portable, wearable, and self‐powered sensing devices.