Water-Processed Gum Arabic Dielectric for Low-Voltage, High-Mobility, and Transient Organic Thin-Film Transistors

Growing concerns about electronic waste underscore the need for materials that combine high performance with environmental sustainability. Here, we report an organic thin-film transistor (OTFT) that incorporates a water-processed gum arabic (GA) dielectric, a natural, biodegradable resin derived from Acacia senegal, to enable eco-friendly device fabrication. The GA dielectric forms defect-free films directly from aqueous solution and exhibits a dielectric constant of approximately 27 at 1 kHz. By optimizing GA concentration, we obtain uniform and stable dielectric layers that substantially enhance charge transport in dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (DNTT) semiconductors, yielding p-type OTFTs operating at ±3 V with high mobilities up to 20.72 cm² V⁻¹ s⁻¹ and negligible hysteresis. Comparative analyses show that GA facilitates improved molecular ordering of DNTT and suppresses trap formation, outperforming conventional PMMA dielectrics. Upon immersion in water, the GA layer dissolves rapidly (within 30 s), leaving the substrate pristine and fulfilling key criteria for transient electronics. This combination of outstanding electrical performance and complete aqueous degradability highlights the potential of GA for scalable fabrication of green, high-performance electronic devices designed to disappear on demand, supporting urgent efforts toward sustainable and transient electronic technologies.