Role of Metal Contacts in Designing High-Performance Monolayer n-Type WSe2 Field Effect Transistors

ABSTRACTIntegrated plastic circuits (IPCs) will become an integral component of future low cost electronics. For low cost processes IPCs have to be made of all-polymer Transistors. We present our recent results on fabrication of Organic Field-Effect Transistors (OFETs) and integrated inverters. Top-gate transistors were fabricated using polymer semiconductors and insulators. The source-drain structures were defined by standard lithography of Au on a flexible plastic film, and on top of these electrodes, poly(3-alkylthiophene) (P3AT) as semiconductor, and poly(4-hydroxystyrene) (PHS) as insulator were homogeneously deposited by spin-coating. The gate electrodes consist of metal contacts. With this simple set-up, the transistors exhibit excellent electric performance with a high source-drain current at source - drain and gate voltages below 30V. The characteristics show very good saturation behaviour for low biases and are comparable to results published for precursor pentacene. With this setup we obtain a mobility of 0.2cm2/Vs for P3AT. Furthermore, we discuss organic integrated inverters exhibiting logic capability. All devices show shelf-lives of several months without encapsulation.

Download Full-text

Molecular Requirements for Printable Organic Semiconductors in 7-Alkyl-2-phenyl[1]benzothieno[3,2-b][1]benzothiophenes (Ph-BTBT-Cn’s)

MRS Advances ◽

10.1557/adv.2016.441 ◽

2016 ◽

Vol 1 (38) ◽

pp. 2653-2658

Author(s):

S. Inoue ◽

H. Minemawari ◽

J. Tsutsumi ◽

T. Hamai ◽

S. Arai ◽

...

Keyword(s):

Chain Length ◽

Organic Semiconductors ◽

Field Effect ◽

High Performance ◽

Carrier Transport ◽

Alkyl Chain ◽

Field Effect Transistors ◽

Systematic Investigation ◽

Alkyl Chain Length

ABSTRACTHere we discuss requirements for high performance and solution processable organic semiconductors, by presenting a systematic investigation of 7-alkyl-2-phenyl[1]benzothieno[3,2-b][1]benzothiophenes (Ph-BTBT-Cn’s). We found that the solubility and thermal properties of Ph-BTBT-Cn’s depend systematically on the substituted alkyl-chain length n. The observed features are well understood in terms of the change of molecular packing motif with n: The compounds with n ≤ 4 do not form independent alkyl chain layers, whereas those with n ≥ 5 form isolated alkyl chain layers. The latter compounds afford a series of isomorphous bilayer-type crystal structures that form two-dimensional carrier transport layers within the crystals. We also show that the Ph-BTBT-C10 afford high performance single-crystalline field-effect transistors the mobility of which reaches as high as 15.9 cm2/Vs. These results demonstrate a crucial role of the substituted alkyl chain length for obtaining high performance organic semiconductors and field-effect transistors.

Download Full-text

The role of metal contacts in the stability of n-type organic field effect transistors

Applied Physics A ◽

10.1007/s00339-014-8652-4 ◽

2014 ◽

Vol 117 (4) ◽

pp. 2235-2240 ◽

Cited By ~ 4

Author(s):

Rizwan Ahmed ◽

Clemens Simbrunner ◽

G. Schwabegger ◽

M. A. Baig ◽

H. Sitter

Keyword(s):

Field Effect ◽

Field Effect Transistors ◽

Organic Field Effect Transistors ◽

Metal Contacts ◽

The Stability

Download Full-text

Faculty Opinions recommendation of DNA-directed nanofabrication of high-performance carbon nanotube field-effect transistors.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.738001907.793575807 ◽

2020 ◽

Author(s):

Bryan Wei

Keyword(s):

Carbon Nanotube ◽

Field Effect ◽

High Performance ◽

Field Effect Transistors

Download Full-text

Polarization-sensitive photodetectors based on three-dimensional molybdenum disulfide (MoS2) field-effect transistors

Nanophotonics ◽

10.1515/nanoph-2020-0401 ◽

2020 ◽

Vol 9 (16) ◽

pp. 4719-4728

Author(s):

Tao Deng ◽

Shasha Li ◽

Yuning Li ◽

Yang Zhang ◽

Jingye Sun ◽

...

Keyword(s):

Molybdenum Disulfide ◽

Field Effect ◽

High Performance ◽

Field Effect Transistors ◽

Three Dimensional ◽

Polarized Light ◽

Optical Field ◽

Two Dimensional ◽

Polarization Ratio ◽

Two Dimensional Materials

AbstractThe molybdenum disulfide (MoS2)-based photodetectors are facing two challenges: the insensitivity to polarized light and the low photoresponsivity. Herein, three-dimensional (3D) field-effect transistors (FETs) based on monolayer MoS2 were fabricated by applying a self–rolled-up technique. The unique microtubular structure makes 3D MoS2 FETs become polarization sensitive. Moreover, the microtubular structure not only offers a natural resonant microcavity to enhance the optical field inside but also increases the light-MoS2 interaction area, resulting in a higher photoresponsivity. Photoresponsivities as high as 23.8 and 2.9 A/W at 395 and 660 nm, respectively, and a comparable polarization ratio of 1.64 were obtained. The fabrication technique of the 3D MoS2 FET could be transferred to other two-dimensional materials, which is very promising for high-performance polarization-sensitive optical and optoelectronic applications.

Download Full-text

Influence of the Electrolyte Salt Concentration on DNA Detection with Graphene Transistors

Biosensors ◽

10.3390/bios11010024 ◽

2021 ◽

Vol 11 (1) ◽

pp. 24

Author(s):

Agnes Purwidyantri ◽

Telma Domingues ◽

Jérôme Borme ◽

Joana Rafaela Guerreiro ◽

Andrey Ipatov ◽

...

Keyword(s):

Phosphate Buffer ◽

Species Interactions ◽

Field Effect ◽

Field Effect Transistors ◽

Limit Of Detection ◽

Debye Length ◽

Intermolecular Forces ◽

Single Layer Graphene ◽

Dna Adsorption

Liquid-gated Graphene Field-Effect Transistors (GFET) are ultrasensitive bio-detection platforms carrying out the graphene’s exceptional intrinsic functionalities. Buffer and dilution factor are prevalent strategies towards the optimum performance of the GFETs. However, beyond the Debye length (λD), the role of the graphene-electrolytes’ ionic species interactions on the DNA behavior at the nanoscale interface is complicated. We studied the characteristics of the GFETs under different ionic strength, pH, and electrolyte type, e.g., phosphate buffer (PB), and phosphate buffer saline (PBS), in an automatic portable built-in system. The electrostatic gating and charge transfer phenomena were inferred from the field-effect measurements of the Dirac point position in single-layer graphene (SLG) transistors transfer curves. Results denote that λD is not the main factor governing the effective nanoscale screening environment. We observed that the longer λD was not the determining characteristic for sensitivity increment and limit of detection (LoD) as demonstrated by different types and ionic strengths of measuring buffers. In the DNA hybridization study, our findings show the role of the additional salts present in PBS, as compared to PB, in increasing graphene electron mobility, electrostatic shielding, intermolecular forces and DNA adsorption kinetics leading to an improved sensitivity.

Download Full-text

Nanonet: Low-temperature-processed tellurium nanowire network for scalable p-type field-effect transistors and a highly sensitive phototransistor array

NPG Asia Materials ◽

10.1038/s41427-021-00314-y ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Muhammad Naqi ◽

Kyung Hwan Choi ◽

Hocheon Yoo ◽

Sudong Chae ◽

Bum Jun Kim ◽

...

Keyword(s):

Low Temperature ◽

Field Effect ◽

High Performance ◽

Field Effect Transistors ◽

Optical Measurements ◽

Electrical Performance ◽

Large Area ◽

Nanowire Network ◽

P Type ◽

Nanowire Networks

AbstractLow-temperature-processed semiconductors are an emerging need for next-generation scalable electronics, and these semiconductors need to feature large-area fabrication, solution processability, high electrical performance, and wide spectral optical absorption properties. Although various strategies of low-temperature-processed n-type semiconductors have been achieved, the development of high-performance p-type semiconductors at low temperature is still limited. Here, we report a unique low-temperature-processed method to synthesize tellurium nanowire networks (Te-nanonets) over a scalable area for the fabrication of high-performance large-area p-type field-effect transistors (FETs) with uniform and stable electrical and optical properties. Maximum mobility of 4.7 cm2/Vs, an on/off current ratio of 1 × 104, and a maximum transconductance of 2.18 µS are achieved. To further demonstrate the applicability of the proposed semiconductor, the electrical performance of a Te-nanonet-based transistor array of 42 devices is also measured, revealing stable and uniform results. Finally, to broaden the applicability of p-type Te-nanonet-based FETs, optical measurements are demonstrated over a wide spectral range, revealing an exceptionally uniform optical performance.

Download Full-text

Elucidating the Role of Water‐Related Traps in the Operation of Polymer Field‐Effect Transistors

Advanced Electronic Materials ◽

10.1002/aelm.202100393 ◽

2021 ◽

pp. 2100393

Author(s):

Hamna F. Iqbal ◽

Matthew Waldrip ◽

Hu Chen ◽

Iain McCulloch ◽

Oana D. Jurchescu

Keyword(s):

Field Effect ◽

Field Effect Transistors

Download Full-text