Multifunctionality of Giant and Long-Lasting Persistent Photoconductivity: Semiconductor鈥揅onductor Transition in Graphene Nanosheets and Amorphous InGaZnO Hybrids

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• 作者：Min-Kun Dai ; Yi-Rou Liou ; Jan-Tien Lian ; Tai-Yuan Lin ; Yang-Fang Chen
• 刊名：ACS Photonics
• 出版年：2015
• 出版时间：August 19, 2015
• 年：2015
• 卷：2
• 期：8
• 页码：1057-1064
• 全文大小：607K
• ISSN：2330-4022

文摘

Composite materials can play a decisive role to reveal novel physical properties and enable to advance new generation technologies. Here, we discover that phototransistors based on the integration of two-dimensional graphene nanosheets (GNSs) and amorphous indium鈥揼allium鈥搝inc鈥搊xide (a-IGZO) semiconductors exhibit a giant photo-to-dark current ratio and long-lasting persistent photoconductivity (PPC). Under the illumination of UV light (350 nm) at 50 mW/cm², a photo-to-dark current ratio up to 2.0 脳 10⁷ was obtained, which is about 3 orders of magnitude higher than its pure a-IGZO device counterpart. Moreover, the GNSs/a-IGZO phototransistor possesses an enduring lifetime up to years for the recovery of the transfer characteristics after switching off the UV light. The giant and long-lasting PPC leads GNSs/a-IGZO to become an excellent conductor with conductivity much better than indium tin oxide. The observed unique features represent a semiconductor鈥揷onductor transition. In addition to next generation flat, flexible, and display, it can open up a wide variety of application, such as transparent electrodes for optoelectronic devices, optical memory, and light harvesting for energy storage. As an example, we demonstrated the operation of optical memory devices, which may lead to the novel application of holographic storage. Our results shown here therefore provide an outstanding new route for the future development of solution-processable semiconducting optoelectronic devices.