Department of Chemical Engineering, Myongji University , 116 Myongji-ro, Cheoin-gu, Yongin-si, Gyeonggi-do 17058, Republic of Korea.
Department of Chemical Engineering, College of Engineering, Kyung Hee University , 1 Seochon-dong, Giheung-gu, Yongin-si, Gyeonggi-do 17104, Republic of Korea.
ACS Appl Mater Interfaces. 2017 May 17;9(19):16375-16380. doi: 10.1021/acsami.7b00714. Epub 2017 May 2.
Reduced graphene oxide quantum dot (rGOQD) devices in formats of capacitor and thin film transistor (TFT) were demonstrated and examined as the first trial to achieve nonambipolar channel property. In addition, through a gold nanoparticle (Au NP) layer embedded between the rGOQD active channel and dielectric layer, memory capacitor and TFT performances were realized by capacitance-voltage (C-V) hysteresis and gate program, erase, and reprogram biases. First, capacitor structure of the rGOQD memory device was constructed to examine memory charging effect featured in hysteretic C-V behavior with a 30 nm dielectric layer of cross-linked poly(vinyl alcohol). For the intervening Au NP charging layer, self-assembled monolayer (SAM) formation of the Au NP was executed to utilize electrostatic interaction by a dip-coating process under ambient environments with a conformal fabrication uniformity. Second, the rGOQD memory TFT device was also constructed in the same format of the Au NPs SAMs on a flexible substrate. Characteristics of the rGOQD TFT output showed novel saturation curves unlike typical graphene-based TFTs. However, The rGOQD TFT device reveals relatively low on/off ratio of 10 and mobility of 5.005 cm/V·s. For the memory capacitor, the flat-band voltage shift (ΔV) was measured as 3.74 V for ±10 V sweep, and for the memory TFT, the threshold voltage shift (ΔV) by the Au NP charging was detected as 7.84 V. In summary, it was concluded that the rGOQD memory device could accomplish an ideal graphene-based memory performance, which could have provided a wide memory window and saturated output characteristics.
还原氧化石墨烯量子点（rGOQD）器件分别以电容器和薄膜晶体管（TFT）的形式得到了展示和研究，这是首次尝试实现非双极性沟道特性。此外，通过在 rGOQD 活性沟道和介电层之间嵌入金纳米颗粒（Au NP）层，实现了基于电容-电压（C-V）滞后和栅极编程、擦除和重编程偏置的记忆电容器和 TFT 性能。首先，构建了 rGOQD 记忆器件的电容器结构，以检查具有交联聚乙烯醇（PVA）30nm 介电层的滞后 C-V 行为所具有的记忆充电效应。对于介入的 Au NP 充电层，通过在环境条件下进行自组装单层（SAM）形成的浸涂工艺，利用静电相互作用，实现了均匀的共形制造。其次，在相同的 Au NPs SAM 格式下，在柔性衬底上构建了 rGOQD 记忆 TFT 器件。rGOQD TFT 输出的特性表现出不同于典型的基于石墨烯 TFT 的新颖饱和曲线。然而，rGOQD TFT 器件的开关比相对较低，为 10，迁移率为 5.005cm/V·s。对于记忆电容器，在±10V 扫频下测量到的平带电压漂移（ΔV）为 3.74V，对于记忆 TFT，通过 Au NP 充电检测到的阈值电压漂移（ΔV）为 7.84V。总之，研究结果表明，rGOQD 记忆器件可以实现理想的基于石墨烯的记忆性能，这可能提供了一个宽的记忆窗口和饱和输出特性。
