Graphene Nanoribbon Field-Effect Transistors with Top-Gate Polymer Dielectrics

Abstract

Graphene nanoribbons (GNRs) have demonstrated great potential for nanoscale devices owing to their excellent electrical properties. However, the application of the GNRs in large-scale devices still remains elusive mainly due to the absence of facile, nonhazardous, and nondestructive transfer methods. Here, we develop a simple acid (HF)-free transfer method for fabricating field-effect transistors (FETs) with a monolayer composed of a random network of GNRs. A polymer layer that is typically used as mechanical support for transferring GNR films is utilized as the gate dielectric. The resultant GNR-FETs exhibit excellent FET characteristics with a large on/off switching current ratio of >10 4 . The transfer process enables the demonstration of the first GNRbased nonvolatile memory. The process offers a simple route for GNRs to be utilized in various optoelectronic devices.

Graphene Strain-Effect Transistor with Colossal ON/OFF Current Ratio Enabled by Reversible Nanocrack Formation in Metal Electrodes on Piezoelectric Substrates

“…The mean and standard deviation values for the ON/OFF current ratio were found to be 3.6 × 10 6 and 4.4 × 10 6 for the electron branch and 2.9 × 10 6 and 2.9 × 10 6 for the hole branch, respectively. In other words, most GSETs offer an ON/OFF current ratio >10 6 for both electron and hole branches when V DS = 100 mV. The device-to-device variation in V ST can be attributed to the random distribution of domains on the PZT substrate.…”

“…We also utilize piezoelectric lead zirconate titanate (PZT) as a gate dielectric to transduce gate voltage into strain for dynamic strain engineering in metal contacts to graphene. We demonstrate strain-induced abrupt switching across 50 GSETs with a mean ON/OFF current ratio of >10 6 , a high transconductance of >100 μS/μm, and a subthreshold swing (SS) of <1 mV/decade with a finite hysteresis window. Figure 1a−b, respectively, shows the 2D schematic and a scanning electron microscope (SEM) image of a GSET.…”

“…To overcome this challenge, several approaches have been investigated to achieve a high ON/OFF current ratio in GFETs. For example, quantum confinement in graphene nanoribbons can lead to the opening of a finite bandgap, ,,, which can be translated into an ON/OFF current ratio of ∼10 3 in GFETs. , GFETs with high-k gate dielectrics such as ferroelectric barium titanate can also demonstrate ON/OFF current ratios of ∼10 4 . Electrochemical modification of the graphene channel through the use of electrolyte gating with honey, organic liquids, etc., can also lead to ON/OFF current ratios exceeding 10 8 in GFETs, albeit with limited yield and relatively poor endurance. , Finally, vertical heterostructure designs of graphene with other semiconducting materials (Si, Ge, WS 2 ) have reported ON/OFF current ratios as high as ∼10 6 . ,,, …”

“…To overcome this challenge, several approaches have been investigated to achieve a high ON/ OFF current ratio in GFETs. For example, quantum confinement in graphene nanoribbons can lead to the opening of a finite bandgap, 4,6,7,16 which can be translated into an ON/ OFF current ratio of ∼10 3 in GFETs. 1,4 GFETs with high-k gate dielectrics such as ferroelectric barium titanate can also demonstrate ON/OFF current ratios of ∼10 4 .…”

Electrochemically Exfoliated Two-Dimensional Nanomaterials for Electronics

“…[9,10] 우수한 f). [1,3,9,[11][12][13][14][15][16][17][18][19][20] 1. h). [22][23][24] 본 접근법은 구조적인 문제와 상변화 문제를 초래하지 않으면서 2차원 소재를 대량으로 생산하는 방 법으로 차세대 전자소자의 대면적 응용을 위한 핵심 소 재 공정으로 주목받고 있다.…”