Giant responsivity of a new InGaZnO ultraviolet thin-film phototransistor based on combined dual gate engineering and surface decorated Ag nanoparticles aspects

In this paper, a new InGaZnO (IGZO) thin-film UV Phototransistor (Photo-TFT) based on both dual material gate (DM) and plasmonic Ag nanoparticles (NPs) is proposed, in hope of combining the beauties of both aspects to achieve enhanced photogeneration/collection efficiency. An accurate drain-current model for the investigated device is developed, where a good agreement with the experimental data is achieved. The optical behavior of IGZO thin-film decorated with Ag NPs is analyzed using 3-D FDTD method. Interestingly, a strategic combination between the developed model and Particle Swarm Optimization (PSO) technique is conducted to find out the appropriate DM gate configuration and the best Ag NPs spatial arrangement offering the highest device Figure of Merits (FoMs). It is revealed that the optimized design showcases giant responsivity exceeding 10(3) A/W and superb detectivity of 6.8 x 10(14) Jones, which are far beyond conventional IGZO Photo-TFTs. These improvements are attributed to localized surface plasmon resonance effects (LSPR), leading to enhance the UV-absorbance capability. Moreover, the optimized DM gate generates intense electric-field in the IGZO channel, allowing the efficient separation and transfer of photo-induced carriers. Therefore, promoting enhanced photogeneration/collection efficiency, this innovative strategy based on decorated Ag NPs combined with DM gate engineering provide a sound pathway for designing potential alternative IGZO Photo-TFT for the future optoelectronic technology. (C) 2020 Elsevier B.V. All rights reserved.