Presentation Information
[9p-A33-10]Radical Molecular Interface Engineering for WSe2 Memtransistors towards Neuromorphic Computing
〇(D)Huiqin Liu1, Durgadevi Elamaran1, Guanting Liu1, Daisuke Kiriya1 (1.Univ. of Tokyo)
Keywords:
Neuromorphics,Transition metal dichalcogenides,Radical molecular interface
Brain-inspired neuromorphic computing, which emulates biological synaptic weights through analog conductance modulation, offers a promising strategy to overcome the increasing computational complexity and energy consumption of conventional von Neumann architectures. Atomically thin two-dimensional semiconductors, such as WSe2 and other transition metal dichalcogenides (TMDs) are promising material platforms for next-generation electronic devices. However, achieving reproducible and controllable conductance modulation in simple, CMOS-compatible 2D devices remains challenging. Here, we introduce ethyl viologen radical (EV+) as a molecular interface for WSe2 transistors. Owing to its unpaired electron and redox-active nature, the molecular interface can function as a dynamic charge reservoir, participating in charge trapping and detrapping during electrical operation. This would enable controllable memristive conductance modulation in WSe2 transistors for artificial synaptic applications. EV radical was generated from dication state via an electrochemistry reduction process. Electron spin resonance (ESR) measurements confirmed the presence of unpaired spins. After mixing with WSe2 fragments, the decreased ESR intensity and low-field shift suggest that the local electronic/spin environment of radical is altered upon contact with WSe2, indicating a possible electronic/spin interaction between radical and WSe2 . Based on that, the radical was introduced at the metal contact interface to fabricate memtransistors for artificial synaptic applications. Current–voltage characteristics (without gate voltage) showed clear hysteresis. The device also showed stable switching over 50 cycles and potentiation/depression behavior under pulse operation, demonstrating its potential for artificial synaptic applications.