Halide Perovskite Quantum Dots Photosensitized-Amorphous Oxide Transistors for Multimodal Synapses

Deployment of novel artificial synapses serves as the crucial unit for building neuromorphic hardware to drive data-intensive applications. Emulation of complex neural behavior through conventional Si-based devices requires a large number of elements which increases fabrication complexity and brings challenges of connectivity. Hence, there is a need to investigate alternative material systems and device architectures for emulating richer neural behavior comprising of lesser elements. Herein, a thin-film transistor-like synaptic device using all-inorganic cesium lead bromide (CsPbBr₃) perovskite quantum dots (QDs) and amorphous indium gallium zinc oxide semiconductor active material is explored for brain-inspired computing. The incorporation of CsPbBr₃ QDs as a photosensitizer aids in realizing light-dependent synaptic memory. Furthermore, type II heterostructure can serve as a basis for electro-optical programming. The proposed artificial synapse demonstrates a materials combination that can decouple optical absorption and charge transport property and provides freedom to tune the spectral region. Harnessing the advantages of novel materials, the devices obey spike-timing-dependent plasticity rules, inculcate associative learning and linear nonvolatile blind updates. This architecture paves way for efficient building of neuromorphic hardware elements with facile tunability and tailorable plasticity.