Khan Taslim, Kandar Santanu, Ali Sazid, Singh Pushpapraj, Horng Ray-Hua, Singh Rajendra
Department of Physics, Indian Institute of Technology Delhi, New Delhi, 110016, India.
International College of Semiconductor Technology (ICST), National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan.
Small. 2025 Apr;21(16):e2500098. doi: 10.1002/smll.202500098. Epub 2025 Mar 5.
As neuromorphic computing systems, which allow for parallel data storage and processing with high area and energy efficiency, show great potential for future storage and in-memory computing technologies. In this article, a high-performance UV detector for artificial optical synapse applications is demonstrated that can selectively detect UV-A and UV-C, with a responsivity of 407 A W. The pyrophototronic effect increases photocurrent dramatically under UV-A irradiation due to heat accumulation in the ZnO layer and ZnGaO's low thermal conductivity. In context of synaptic device, it's shown that a ZnO/ZnGaO heterostructure can be used as a light-tunable charge trapping medium to create an electro-photoactive synapse. The photogating effect enables via pyrophototronic, which traps photogenerated electrons within the ZnO/ZnGaO interface, and drives synaptic activity, as proven by electrical techniques based on UV-A stimuli. This phenomenon results in a selective detection capability for UV-A over UV-C. Thermally produced pyrophototronic effect synaptic plasticity, simulating biological synapse activity. Persistent photoconductivity under 380 (UV-A) nm UV light mimics synaptic processes, with low thermal conductivity enhancing synaptic weight updates during learning and forgetting. These findings show the possibility of using ZnO/ZnGaO heterostructures into artificial optoelectronic synapse systems controlled by thermal dynamics.
作为能够实现并行数据存储和处理且具有高面积和能源效率的神经形态计算系统，在未来存储和内存计算技术方面展现出巨大潜力。在本文中，展示了一种用于人工光学突触应用的高性能紫外探测器，它能够选择性地检测UV-A和UV-C，响应度为407 A/W。由于ZnO层中的热量积累以及ZnGaO的低热导率，光热电子效应在UV-A照射下会显著增加光电流。在突触器件的背景下，表明ZnO/ZnGaO异质结构可作为光可调电荷俘获介质来创建电光活性突触。光门控效应通过光热电子实现，它将光生电子俘获在ZnO/ZnGaO界面内，并驱动突触活动，这已通过基于UV-A刺激的电学技术得到证实。这种现象导致对UV-A具有高于UV-C的选择性检测能力。热产生的光热电子效应突触可塑性，模拟生物突触活动。在380（UV-A）nm紫外光下的持久光电导模拟突触过程，低热导率在学习和遗忘过程中增强突触权重更新。这些发现表明了将ZnO/ZnGaO异质结构用于由热动力学控制的人工光电突触系统的可能性。
