Flexible InGaZnO Thin-Film Transistors With Gelatin Gate Dielectric for Nonvolatile Memory

• Published in: IEEE journal on flexible electronics Vol. 4; no. 5; pp. 188 - 193
• Main Authors: Konwar, Gargi, Lanthaler, Albert Heinrich, Singh, Ritesh Kumar, Catania, Federica, Munzenrieder, Niko, Cantarella, Giuseppe, Tiwari, Shree Prakash
• Format: Journal Article
• Language: English
• Published: IEEE 01.05.2025
• Subjects: Bending; Dielectrics; Gelatin dielectric; green electronics; Humidity; Hysteresis; indium gallium zinc oxide (InGaZnO); Ions; Logic gates; Nonvolatile memory; Substrates; Thin film transistors; thin-film transistor (TFT); Transistors
• ISSN: 2768-167X; 2768-167X
• DOI: 10.1109/JFLEX.2025.3528306

Recently, the use of natural materials in device fabrication has become a significant trend in advancing eco-friendly and sustainable electronics, to achieve technologies with low carbon footprints and yet reliable functionality. This work demonstrates utilization of gelatin, a natural protein, as a gate dielectric, in combination with indium gallium zinc oxide (InGaZnO) semiconductor, to fabricate top-gated flexible thin-film transistors (TFTs). More specifically, these devices exhibit nonvolatile memory characteristics for 10 V operation upon application of a voltage sweep of ±10 V, with a maximum memory window (MW) of <inline-formula> <tex-math notation="LaTeX">\approx 12 </tex-math></inline-formula> V and repetition for 100 continuous scans. Moreover, consistent static retention was obtained with a current on-off ratio of <inline-formula> <tex-math notation="LaTeX">{\gt }10^{5} </tex-math></inline-formula> for 3 h. The hygroscopic nature of gelatin enabled these devices to demonstrate reliable response as humidity sensor upon exposure to a humidity pulse (in the range between 42% and 90% relative humidity). In addition, TFTs demonstrated functionality during bending condition (down to 7 mm bending radius) with 8 months-long shelf-life.