Novel Multimodal Transistor

About

Introduction: Printed electronics on flexible substrates is of growing interest, specifically for large-area and disposable electronics, advanced or low cost display technology, sensors, wearables and other applications where printed and/or roll-to-roll (R2R) processing would allow for quick, cost-effective fabrication. However, several limitations have been encountered using conventional TFTs, including: Poor device performance and uniformity due to material limitations when under electrical and mechanical stress, making practical behaviour far from ideal and complicating circuit designs. Performance variations due to layer registration, controllable only at great cost. Added circuit complexity required by compensation strategy to mitigate the above. Reduced production yield, as probability of circuit failure increases with component count. Non-idealities inherent in the device physics, such as quadratic output-to-input dependence or loss in performance due to contact-induced energy barriers. Technology: University of Surrey academic Dr Radu Sporea and postgraduate researcher Eva Bestelink have developed a patent-pending multimodal transistor (MMT). This new transistor architecture features a new operating philosophy and is material agnostic, while being largely backward compatible with existing technology. The unique operating mechanism provides: linear output current dependence on input voltage; lower series operating voltages and hence low power consumption; high output impedance, hence high gain; improved operating speeds; uniformity with imprecise fabrication methods, such as in R2R; and compact circuit design with new functionality (e.g. unsupervised linear analog control). In addition to suitability for existing applications, exploiting MMT functionality, either exclusively or alongside conventional TFTs, would overhaul TFT circuit design beyond conventional displays: e.g. sensing, analog computation, hardware AI, and hardware learning. As such, it may overcome technological challenges, as well as form the next step in the evolution of maturing technology (e.g. displays) and numerous emerging or new low-cost flexible electronic applications, e.g. energy efficient sensor readout coupled with control incorporating unsupervised feedback. Applications/Benefits: Provides new functionality, overcoming limitations of existing devices, in low-cost flexible electronic applications beyond traditional digital and analog operation: hardware learning, control and neuromorphic operation. Versatile, robust, low power, high-speed, linear, distortion-free behaviour resulting in significant circuit simplification for a given functionality, e.g. multi-level logic D-A conversion in a single device. An enabling technology, offering superior performance with increased transistor density and improved speed at reduced costs.