Organic Thin Film Transistors for Sustainable Electronics

The escalating problem of electronic waste (e-waste) demands the development of sustainable and high-performance electronic systems. Conventional flexible devices rely on non-degradable plastic substrates, which comprise the majority of e-waste. Although biodegradable substrates have been explored, they often require additional non-degradable basement layers to overcome challenges like surface roughness, moisture sensitivity, and porosity that hinder direct device fabrication. In this work, we demonstrate organic thin-film transistors (OTFTs) fabricated directly on biodegradable polymer cellulose acetate (degree of substitution 2.4) without any basement layer. The devices exhibit an on/off current ratio of 10³, a subthreshold swing of 1.2 V decade⁻¹, and field effect mobility on the order of 10⁻² cm² V⁻¹ s⁻¹, confirming that device performance is not compromised by the absence of a planarization layer. This approach preserves complete biodegradability while simplifying the fabrication process. All processing steps were performed under ambient conditions, demonstrating that high-performance, fully biodegradable electronics can be realized through simplified, sustainable, and eco-friendly manufacturing routes.