An Intrinsically Stretchable Nanowire Photodetector with a Fully Embedded Structure
An Intrinsically Stretchable Nanowire Photodetector with a Fully Embedded Structure
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DOI：
10.1002/adma.201304226
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发表时间：
2014-02-01
影响因子：
29.4
通讯作者：
Lee, Pooi See
中科院分区：
文献类型：
--
作者：
Yan, Chaoyi;Wang, Jiangxin;Lee, Pooi See
可拉伸光电子学是一种可以弯曲，扭曲，折叠和拉伸的电子形式，有望开辟前所未有的应用，这些应用是现有刚性技术无法实现的，例如植入式生物医学设备，可穿戴电子设备，智能服装和机器人系统的感觉皮肤。[1]几种类型的可拉伸光电器件已经成功地被证明，包括可拉伸发光二极管（LED），[2-6]可拉伸光电探测器，[7-9]可拉伸太阳能电池，[10-12]等。光电探测器是一种用于感测光的电子器件，它们在消费电子产品如数码相机中有广泛的应用。现有技术采用刚性平面衬底上的单晶硅器件。[9]这将是极大的兴趣，使这些光电探测器可拉伸的创新应用。例如，可以将可伸缩的光电探测器植入人眼，这样人们只需眨眼就可以拍摄数字图像。这些植入式光电探测器还可以帮助盲人恢复视觉。与现有的集成在平面电路板上的光电探测器相比，柔软且可拉伸的器件可以变形并符合诸如人眼的半球形透镜的表面，并实现诸如更宽的视场、更低的像差和可调焦距的新功能。[8，9，13]最近，使用可压缩互连来制造基于单晶硅的可拉伸光电探测器，并且该器件可以安装到眼球透镜上以提高成像能力。[8，9]在此，我们提出了另一种基于纳米线弹性导体制造高度可拉伸光电探测器的策略。光电探测器采用了一种本质上可拉伸的器件结构，其电极和检测通道都完全嵌入弹性体基质中，并表现出高达100%的优异拉伸性。通过适当的材料和结构设计可以实现赋予最初刚性的装置可拉伸性。[1]已经报道了基于加载有导电填料（例如Ag纳米颗粒、碳纳米管）的弹性体的可拉伸材料。[3，14-16]设计可拉伸结构是一种更常用的策略。例如，通过蒸发[17]印刷[18，19]或植入[20]直接沉积在弹性体基底上的金属膜被发现是可拉伸的。金属导电材料[9，21]和石墨烯导电材料[4，22]的弯曲和蛇形结构也被设计为实现所需的拉伸性。特别是，可伸缩纳米线和纳米管网络已被证明是可伸缩电子产品的有前途的候选者。[5，14，23-25]在膨胀网络内的互连纳米线可以有效地适应应变，并且在它们破裂成补丁之前显示出相当好的拉伸耐受性。到目前为止，已有多个研究小组报道了可拉伸碳纳米管（CNT）或纳米线网络的制备[5，14，23-25]，然而，大多数研究仅集中在可拉伸电极的演示上，而将不同功能的纳米线组件组装成完整器件的工作非常有限，特别是尚未报道可拉伸纳米线光电探测器的研究。在这项工作中，我们介绍了一种光刻过滤方法来制造基于嵌入式纳米线的可拉伸光电探测器。该方法是快速和有效的制造均匀的纳米线薄膜，它也允许多个图案化的纳米线层的构造复杂的器件结构，这是一个关键的优势，现有的“铸造…
Stretchable optoelectronics, a form of electronics that can be bended, twisted, folded and stretched, hold the promise to open up unprecedented applications, which are unreachable with existing rigid technology, such as implantable biomedical devices, wearable electronics, smart clothes, and sensory skin for robotic system.[1] Several types of stretchable optoelectronic devices have been successfully demonstrated, including stretchable light-emitting diodes (LEDs),[2–6] stretchable photodetectors,[7–9] stretchable solar cells,[10–12] etc. Photodetectors are a type of electronic device for sensing light and they have found broad applications in consumer electronics such as digital cameras. State-of-the-art technologies employ single-crystal silicon devices on rigid planar substrates.[9] It would be of great interest to make those photodetectors stretchable for innovative applications. For example, stretchable photodetectors could be implanted on human eyes so that one can take digital images by simply blinking. Those implantable photodetectors can also help blind people to regain their visual senses. Compared with existing photodetectors integrated on planar circuit boards, the soft and stretchable devices can deform and comply to surfaces such as the hemispherical lens of human eye and enable new functionalities such as wider field of view, lower aberrations and tunable focal lengths.[8, 9, 13] Recently, stretchable photodetectors based on single-crystal silicon were fabricated using compressible interconnects, and the devices can be mounted onto an eye-ball lens to improve the imaging capability.[8, 9] Herein we present another strategy for fabricating highly-stretchable photo detectors based on nanowire elastic conductors. The photo detectors employ an intrinsically stretchable device structure with both electrodes and detection channels fully embedded in an elastomer matrix and exhibit an excellent stretchability up to 100%. Imparting stretchability to originally rigid devices can be achieved by proper material and structural designs.[1] Stretchable materials based on elastomers loaded with conductive fillers (such as Ag nanoparticles, carbon nanotubes) have been reported.[3, 14–16] Designing stretchable structures is a more commonly employed strategy. For example, metallic films directly deposited on elastomer substrates via evaporation,[17] printing [18, 19] or implantation [20] were found to be stretchable. Buckled and serpentine structures of metal [9, 21] and graphene [4, 22] conducting materials were also designed to achieve desired stretchability. Especially, percolating nanowire and nanotube networks have been shown to be promising candidates for stretchable electronics.[5, 14, 23–25] The interconnected nanowires within the percolating network can effectively accommodate strain and show fairly good tolerance to stretching before they rupture into patches. To date, several groups have reported the fabrication of stretchable carbon nanotube (CNT) or nanowire networks,[5, 14, 23–25] however, most of them focused on the demonstration of stretchable electrodes only, and very limited work on the assembly of different functional nanowire components into complete devices can be found. Especially, no studies on stretchable nanowire photodetectors have been reported. In this work, we introduce a lithographic filtration method to fabricate stretchable photodetectors based on embedded nanowires. The method is fast and effective for the fabrication of uniform nanowire films, and it also allows facile integration of multiple patterned nanowire layers for the construction of complex device structures, which is a key advantage over existing “casting …