Ga<sub>2</sub>O<sub>3</sub>-Based Optoelectronic Memristor and Memcapacitor Synapse for In-Memory Sensing and Computing Applications

This study presents the fabrication and characterization of a dual-functional Pt/Ga<sub>2</sub>O<sub>3</sub>/Pt optoelectronic synaptic device, capable of operating as both a memristor and a memcapacitor. We detail the optimized radio frequency (RF) sputtering parameters, inc...

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Main Authors: Hye Jin Lee, Jeong-Hyeon Kim, Seung Hun Lee, Sung-Nam Lee
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Nanomaterials
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Online Access:https://www.mdpi.com/2079-4991/14/23/1972
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author Hye Jin Lee
Jeong-Hyeon Kim
Seung Hun Lee
Sung-Nam Lee
author_facet Hye Jin Lee
Jeong-Hyeon Kim
Seung Hun Lee
Sung-Nam Lee
author_sort Hye Jin Lee
collection DOAJ
description This study presents the fabrication and characterization of a dual-functional Pt/Ga<sub>2</sub>O<sub>3</sub>/Pt optoelectronic synaptic device, capable of operating as both a memristor and a memcapacitor. We detail the optimized radio frequency (RF) sputtering parameters, including a base pressure of 8.7 × 10<sup>−7</sup> Torr, RF power of 100 W, working pressure of 3 mTorr, and the use of high-purity Ga<sub>2</sub>O<sub>3</sub> and Pt targets. These precisely controlled conditions facilitated the formation of an amorphous Ga<sub>2</sub>O<sub>3</sub> thin film, as confirmed by XRD and AFM analyses, which demonstrated notable optical and electrical properties, including light absorption properties in the visible spectrum. The device demonstrated distinct resistive and capacitive switching behaviors, with memory characteristics highly dependent on the wavelength of the applied light. Ultraviolet (365 nm) exposure facilitated long-term memory retention, while visible light (660 nm) supported short-term memory behavior. Paired-pulse facilitation (PPF) measurements revealed that capacitance showed slower decay rates than EPSC, suggesting a more stable memory performance due to the dynamics of carrier trapping and detrapping at the insulator interface. Learning simulations further highlighted the efficiency of these devices, with improved memory retention upon repeated exposure to UV light pulses. Visual encoding simulations on a 3 × 3 pixel array also demonstrated effective multi-level memory storage using varying light intensities. These findings suggest that Ga<sub>2</sub>O<sub>3</sub>-based memristor and memcapacitor devices have significant potential for neuromorphic applications, offering tunable memory performance across various wavelengths from ultraviolet to red.
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spelling doaj-art-75cdbc76bb764cd08a7ed1cb2c72e55d2024-12-13T16:29:36ZengMDPI AGNanomaterials2079-49912024-12-011423197210.3390/nano14231972Ga<sub>2</sub>O<sub>3</sub>-Based Optoelectronic Memristor and Memcapacitor Synapse for In-Memory Sensing and Computing ApplicationsHye Jin Lee0Jeong-Hyeon Kim1Seung Hun Lee2Sung-Nam Lee3Department of IT & Semiconductor Convergence Engineering, Tech University of Korea, Siheung 15073, Republic of KoreaDepartment of IT & Semiconductor Convergence Engineering, Tech University of Korea, Siheung 15073, Republic of KoreaDepartment of IT & Semiconductor Convergence Engineering, Tech University of Korea, Siheung 15073, Republic of KoreaDepartment of IT & Semiconductor Convergence Engineering, Tech University of Korea, Siheung 15073, Republic of KoreaThis study presents the fabrication and characterization of a dual-functional Pt/Ga<sub>2</sub>O<sub>3</sub>/Pt optoelectronic synaptic device, capable of operating as both a memristor and a memcapacitor. We detail the optimized radio frequency (RF) sputtering parameters, including a base pressure of 8.7 × 10<sup>−7</sup> Torr, RF power of 100 W, working pressure of 3 mTorr, and the use of high-purity Ga<sub>2</sub>O<sub>3</sub> and Pt targets. These precisely controlled conditions facilitated the formation of an amorphous Ga<sub>2</sub>O<sub>3</sub> thin film, as confirmed by XRD and AFM analyses, which demonstrated notable optical and electrical properties, including light absorption properties in the visible spectrum. The device demonstrated distinct resistive and capacitive switching behaviors, with memory characteristics highly dependent on the wavelength of the applied light. Ultraviolet (365 nm) exposure facilitated long-term memory retention, while visible light (660 nm) supported short-term memory behavior. Paired-pulse facilitation (PPF) measurements revealed that capacitance showed slower decay rates than EPSC, suggesting a more stable memory performance due to the dynamics of carrier trapping and detrapping at the insulator interface. Learning simulations further highlighted the efficiency of these devices, with improved memory retention upon repeated exposure to UV light pulses. Visual encoding simulations on a 3 × 3 pixel array also demonstrated effective multi-level memory storage using varying light intensities. These findings suggest that Ga<sub>2</sub>O<sub>3</sub>-based memristor and memcapacitor devices have significant potential for neuromorphic applications, offering tunable memory performance across various wavelengths from ultraviolet to red.https://www.mdpi.com/2079-4991/14/23/1972Ga<sub>2</sub>O<sub>3</sub>memristormemcapacitoroptoelectronic synapse
spellingShingle Hye Jin Lee
Jeong-Hyeon Kim
Seung Hun Lee
Sung-Nam Lee
Ga<sub>2</sub>O<sub>3</sub>-Based Optoelectronic Memristor and Memcapacitor Synapse for In-Memory Sensing and Computing Applications
Nanomaterials
Ga<sub>2</sub>O<sub>3</sub>
memristor
memcapacitor
optoelectronic synapse
title Ga<sub>2</sub>O<sub>3</sub>-Based Optoelectronic Memristor and Memcapacitor Synapse for In-Memory Sensing and Computing Applications
title_full Ga<sub>2</sub>O<sub>3</sub>-Based Optoelectronic Memristor and Memcapacitor Synapse for In-Memory Sensing and Computing Applications
title_fullStr Ga<sub>2</sub>O<sub>3</sub>-Based Optoelectronic Memristor and Memcapacitor Synapse for In-Memory Sensing and Computing Applications
title_full_unstemmed Ga<sub>2</sub>O<sub>3</sub>-Based Optoelectronic Memristor and Memcapacitor Synapse for In-Memory Sensing and Computing Applications
title_short Ga<sub>2</sub>O<sub>3</sub>-Based Optoelectronic Memristor and Memcapacitor Synapse for In-Memory Sensing and Computing Applications
title_sort ga sub 2 sub o sub 3 sub based optoelectronic memristor and memcapacitor synapse for in memory sensing and computing applications
topic Ga<sub>2</sub>O<sub>3</sub>
memristor
memcapacitor
optoelectronic synapse
url https://www.mdpi.com/2079-4991/14/23/1972
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