Department of Electrical and Electronics Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea.
Department of Chemistry and Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA.
Adv Mater. 2022 Mar;34(12):e2108979. doi: 10.1002/adma.202108979. Epub 2022 Feb 10.
Artificial photonic synapses are emerging as a promising implementation to emulate the human visual cognitive system by consolidating a series of processes for sensing and memorizing visual information into one system. In particular, mimicking retinal functions such as multispectral color perception and controllable nonvolatility is important for realizing artificial visual systems. However, many studies to date have focused on monochromatic-light-based photonic synapses, and thus, the emulation of color discrimination capability remains an important challenge for visual intelligence. Here, an artificial multispectral color recognition system by employing heterojunction photosynaptic transistors consisting of ratio-controllable mixed quantum dot (M-QD) photoabsorbers and metal-oxide semiconducting channels is proposed. The biological photoreceptor inspires M-QD photoabsorbers with a precisely designed red (R), green (G), and blue (B)-QD ratio, enabling full-range visible color recognition with high photo-to-electric conversion efficiency. In addition, adjustable synaptic plasticity by modulating gate bias allows multiple nonvolatile-to-volatile memory conversion, leading to chromatic control in the artificial photonic synapse. To ensure the viability of the developed proof of concept, a 7 × 7 pixelated photonic synapse array capable of performing outstanding color image recognition based on adjustable wavelength-dependent volatility conversion is demonstrated.
人工光子突触作为一种有前途的实现方式，通过将一系列用于感知和记忆视觉信息的过程整合到一个系统中，正在模仿人类视觉认知系统。特别是，模拟视网膜功能，如多光谱色觉和可控制的非易失性，对于实现人工视觉系统非常重要。然而，迄今为止的许多研究都集中在基于单色光的光子突触上，因此，颜色识别能力的模拟仍然是视觉智能的一个重要挑战。在这里，我们提出了一种基于异质结光突触晶体管的人工多光谱颜色识别系统，该晶体管由可控制混合量子点（M-QD）光吸收器和金属氧化物半导体通道组成。生物光感受器采用精确设计的红（R）、绿（G）和蓝（B）-QD 比的 M-QD 光吸收器激发，实现了具有高光电转换效率的全可见光谱颜色识别。此外，通过调节栅极偏压实现可调谐的突触可塑性，允许多次非易失性到易失性存储转换，从而实现人工光子突触中的颜色控制。为了确保所提出概念验证的可行性，展示了一个 7×7 像素的光子突触阵列，该阵列能够基于可调谐波长相关的易失性转换来执行出色的彩色图像识别。
