Scandium Nitride as a Gateway III‐Nitride Semiconductor for both Excitatory and Inhibitory Optoelectronic Artificial Synaptic Devices

Abstract

Traditional computation based on von Neumann architecture is limited by time and energy consumption due to data transfer between the storage and the processing units. The von Neumann architecture is also inefficient in solving unstructured, probabilistic, and real‐time problems. To address these challenges, a new brain‐inspired neuromorphic computational architecture is required. Due to the absence of resistance–capacitance delay, high bandwidth, and low power consumption, optoelectronic artificial synaptic devices are highly attractive. Yet, stable, scalable, and complementary metal–oxide–semiconductor (CMOS)‐compatible materials exhibiting both inhibitory and excitatory optoelectronic synaptic functionalities have not been demonstrated. Here, epitaxial CMOS‐compatible scandium nitride (ScN) optoelectronic artificial synaptic devices that emulate both inhibitory and excitatory biological synaptic activities are presented. The negative and positive persistent photoconductivity of undoped and magnesium‐doped ScN is equated to the inhibitory and excitatory synaptic plasticity, respectively, which leads to functionalities like learning–forgetting, frequency‐selective optical filtering, frequency‐dependent potentiation and depression, Hebbian learning, and logic‐gate operations. Temperature‐dependent photoresponse and photo‐Hall measurements reveal that scattering of photogenerated carriers from charged defect centers results in negative photoconductivity in undoped degenerate ScN. This work opens up the possibility of utilizing a group‐III epitaxial semiconducting nitride material with inhibitory and excitatory optoelectronic synaptic functionalities for practical neuromorphic applications.

Study of the Adsorption and Separation Behavior of Scandium and Zirconium by Trialkyl Phosphine Oxide-Modified Resins in Sulfuric and Hydrochloric Acid Media

“…Recently, scandium has been utilized as a material for aero-engines and spacecraft, owing to its excellent resistance to high temperatures and corrosion, along with its high strength and resistance to deformation [3][4][5]. Furthermore, the properties of scandium enabled it to play a crucial role in various fields, including catalytic materials [6,7], electronic information [8,9], luminescent materials [10], and hydrogen storage materials [11,12]. Despite scandium's wide range of applications, its availability is limited.…”

High‐Entropy Perovskite Oxide Photonic Synapses

“…[12][13][14] Among them, photonic synaptic devices, one of the basic building blocks for the hardware implementation of neuromorphic computing, have recently attracted significant attention. [15][16][17][18][19][20][21][22][23][24] In comparison to their electronic counterparts, photonic synaptic devices have the potential advantages of wide bandwidth, excellent interconnectivity, and global regulation of synapses. Additionally, photonic synaptic devices with the capability of visual sensing, signal processing and memory are regarded as potential candidates for mimicking the human visual system in a single device.…”

Demonstration of compensated n-type scandium nitride Schottky diodes

“…The positive and negative photoconductivity in ScN is utilized to demonstrate optoelectronic artificial synapses with inhibitory and excitatory synaptic junctions. Such ScN-based optoelectronic synapses have demonstrated short-term memory and long-term memory, paired pulse facilitation and depression, Hebbian learning and logic gate operation, etc [42].…”