Excellent Positive Bias‐Stress Stability of Electrolyte‐Gated Amorphous Oxide Transistors for Long‐Term Stable High‐Power Applications

Printed thin‐film transistors (TFTs) aim to address specific applications in wearable/consumer electronics. Within the printed electronics domain, electrolyte gating has recently attracted wide attention as the gel electrolytes are easy to print and cure, thermally/ environmentally stable, and offer sufficiently high operation frequency necessary for the targeted applications. However, so far, with electrolyte‐gated TFTs (EGFETs), the researchers have primarily focused on the near‐OFF state logic operation, whereas their ON‐state operation or bias‐stress stability has rarely been investigated. In contrast, here we present, a detailed study on the positive bias‐stress stability of inkjet‐printed composite solid polymer electrolyte (CSPE)‐gated TFTs with three different indium‐rich oxide systems, c ‐In 2 O 3 , a ‐IGO, and a ‐IGZO. The findings suggest that a ‐IGO is the optimal solution to obtain spatial homogeneity and excellent long‐term bias‐stress stability, without compromising on the TFT performance. Here, even after 12 h of biasing, a nominal Δ I D,ON ≈10%, Δ V T < 0.25 V have been observed. Furthermore, the load‐bearing capacity of the EGTFTs has been demonstrated by illuminating 54 LEDs for 6 h, with a single a ‐IGO‐based TFT. Next, the integration of the EGTFTs with GaN‐based micro‐LEDs has also been demonstrated. This study paves the way towards real‐life applications, e.g., CSPE‐gated TFT backplanes for all‐printed flexible displays.