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Ercan E, Hung CC, Li GS, Yang YF, Lin YC, Chen WC. Molecular template growth of organic heterojunctions to tailor visual neuroplasticity for high performance phototransistors with ultralow energy consumption. NANOSCALE HORIZONS 2023; 8:632-640. [PMID: 36866736 DOI: 10.1039/d2nh00597b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The optical and charge transport properties of organic semiconductors are strongly influenced by their morphology and molecular structures. Here we report the influence of a molecular template strategy on anisotropic control via weak epitaxial growth of a semiconducting channel for a dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT)/para-sexiphenyl (p-6P) heterojunction. The aim is to improve charge transport and trapping, to enable tailoring of visual neuroplasticity. The proposed phototransistor devices, comprising a molecular heterojunction with optimized molecular template thickness, exhibited an excellent memory ratio (ION/IOFF) and retention characteristics in response to light stimulation, owing to the enhanced orientation/packing of DNTT molecules and a favorable match between the LUMO/HOMO levels of p-6P and DNTT. The best performing heterojunction exhibits visual synaptic functionalities, including an extremely high pair-pulse facilitation index of ∼206%, ultralow energy consumption of 0.54 fJ, and zero-gate operation, under ultrashort pulse light stimulation to mimic human-like sensing, computing, and memory functions. An array of heterojunction photosynapses possess a high degree of visual pattern recognition and learning, to mimic the neuroplasticity of human brain activities through a rehearsal learning process. This study provides a guide to the design of molecular heterojunctions for tailoring high-performance photonic memory and synapses for neuromorphic computing and artificial intelligence systems.
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Affiliation(s)
- Ender Ercan
- Department of Chemical Engineering, National Taiwan University, Taipei, 10617, Taiwan.
- Advanced Research Center of Green Materials Science and Technology, National Taiwan University, Taipei, 10617, Taiwan
| | - Chih-Chien Hung
- Advanced Research Center of Green Materials Science and Technology, National Taiwan University, Taipei, 10617, Taiwan
| | - Guan-Syuan Li
- Department of Chemical Engineering, National Taiwan University, Taipei, 10617, Taiwan.
| | - Yun-Fang Yang
- Department of Chemical Engineering, National Taiwan University, Taipei, 10617, Taiwan.
| | - Yan-Cheng Lin
- Department of Chemical Engineering, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Wen-Chang Chen
- Department of Chemical Engineering, National Taiwan University, Taipei, 10617, Taiwan.
- Advanced Research Center of Green Materials Science and Technology, National Taiwan University, Taipei, 10617, Taiwan
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