Small
·
2023
·Vol. 20
·期 21
·2309626
·
IF 13.3
Boyu Xu,Dan Guo,Weikang Dong,Huiying Gao,Peng Zhu,Zhiwei Wang,Kenji Watanabe,Takashi Taniguchi,Zhaochu Luo,Fawei Zheng,Shoujun Zheng,Jiadong Zhou
Floating gate memory (FGM), composed of van der Waals (vdW) junctions with an atomically thin floating layer for charge storage, is widely employed to develop logic-in memories and in-sensor computing devices. Most research efforts of FGM are spent on achieving long-term charge storage and fast reading/writing for flash and random-access memory. However, dynamic modulation of memory time via a tunneling barrier and vdW interfaces, which is critical for synaptic computing and machine vision, is still lacking. Here, a van der Waals short-term memory with tunable memory windows and retention times from milliseconds to thousands of seconds is reported, which is approximately exponentially proportional to the thickness h-BN (hexagonal boron nitride) barrier. The specific h-BN barrier with fruitful gap states provides charge release channels for trapped charges, making the vdW device switchable between positive photoconductance and negative photoconductance with a broadband light from IR to UV range. The dynamic short-term memory with tunable photo response highlights the design strategy of novel vdW memory vis interface engineering for further intelligent information storage and optoelectronic detection.
研究领域:
材料科学
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电子工程
·
光电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Yating Zhu,Fan Wang,Jiayin Wang,Kaijia Xu,Yinyin Qian
The negative photoconductivity (NPC) effect is becoming an increasingly significant factor in the development of next-generation optoelectronics. However, research in the field of NPC-dominated optoelectronics remains in its infancy and frequently encounters challenges related to fabrication complexity, slow photoresponse speed, instability, and a limited spectral response range. Herein, a Cs 3 Bi 2 I 9 /Au heterostructure nanocomposite was prepared via a simple self-assembly process utilizing electrostatic interactions with Au nanoparticles (NPs) and lead-free Cs 3 Bi 2 I 9 nanoplates. The Cs 3 Bi 2 I 9 /Au nanocomposite-based photodetectors (PDs) demonstrate a broadband photoresponse (405–1550 nm), enhanced rise/fall times (27.2/40.0 µs), and reduced noise density (4.7 × 10 −13 A/Hz 1/2 at 1 Hz). In contrast to the positive photoconductivity (PPC) effect observed in colloidally synthesized Cs 3 Bi 2 I 9 nanoplate-based PDs, the NPC can be attributed to the decrease in photocurrent under light illumination during the processes of recombination and trapping of photogenerated carriers induced by the incorporation of Au NPs. These findings are expected to provide valuable insights into achieving high-performance NPC-dominated PDs by regulating the dynamics of photogenerated carriers in perovskite heterostructures.
研究领域:
材料科学
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光电子学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS CHEMISTRY
·
2011
·Vol. 21
·期 18
·6736-6741
·
IF 5.101
Xiwei Zhang,Jiansheng Jie,Zhi Wang,Chunyan Wu,Li Wang,Qiang Peng,Yongqiang Yu,Peng Jiang,Chao Xie
Single-crystal p-type ZnSe nanowires (NWs) with zinc blende structure and [21–1] growth direction were synthesized by using bismuth (Bi) as dopant via a thermal co-evaporation method. The ZnSe : Bi NWs showed evident p-type conductivity with hole concentration up to 4.1 × 1018 cm−3 after the acceptor activation. Negative photoconductivity was first investigated in the p-ZnSe NWs, i.e., the conductivity of the NWs under light was dramatically lower than that in the dark. Surface effects arising from oxygen absorption and photo-desorption were suggested to be responsible for this. By using Al as the Schottky gate, high-performance nano-metal-semiconductor field-effect transistors (nanoMESFETs) were constructed, and measurements on the Al/p-ZnSe NW Schottky diode also revealed the bias-dependent photoresponse. It is expected that the p-type ZnSe : Bi NWs will have great potential in nano-optoelectronic applications.
研究领域:
材料科学
·
半导体物理
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纳米技术
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光电子学
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凝聚态物理
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·Vol. 35
·期 38
·2504250
·
IF 19
Shuwen Xin,Tianyu Wang,Kunpeng Dou,Lingyan Zheng,Liren Wu,Qi Chen,Shaohua Ji,Guanglong Ding,Ramakrishna Seeram,Ye Zhou,Fengyun Wang
Neuromorphic visual systems, integrating image information acquisition, processing, and storage, hold significant potential for applications in smart security, healthcare, and other fields. Currently, commercial human visual prosthetic systems primarily utilize Si-based CMOS logic circuits to simulate synaptic functions. Compared to traditional Si-based materials, metal oxide nanowires offer unique advantages, such as a larger specific surface area and sustained photoconductivity. However, artificial synaptic devices based on metal oxide nanowires can only achieve unidirectional photoresponse enhancement, posing challenges in mimicking hyperpolarization behavior of cone and rod cells and further developing image classification and recognition functions. Herein, an artificial photo-synaptic device with negative photoconductivity based on metal oxide nanowires/perovskite quantum dots heterojunction fabricated via low-cost electrospinning is proposed. The carrier dynamics process is investigated using advanced characterization techniques. It is revealed that the negative photoconductivity is induced by heterojunction-associated conduction carrier consumption. Based on the device array, the optical encryption function is achieved. The array with adjustable conductivity is used to develop an artificial vision system, reducing redundant data and noise while improving recognition accuracy from 51% to 99%. This study highlights the promising potential of optoelectronic synaptic devices based on metal oxide nanowires and perovskite heterojunctions for artificial visual systems.
研究领域:
神经形态工程
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光电子学
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纳米材料
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人工智能硬件
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视觉感知系统
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）