Optimizing Pentacene Growth in Low-Voltage Organic Thin-Film Transistors Prepared by Dry Fabrication Techniques

Gupta, Swati; Chinnam, Krishna Chytanya; Zelzer, Mischa; Ulijn, Rein V.; Glesková, Helena

doi:10.1557/opl.2012.1556

Cited by 3 publications

(3 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Following the adsorption of the hybrid layer, an upper tunnel barrier was added by deposing 6 nm of Al 2 O 3 in two steps; the first layer was 4 nm thick followed by another layer of 2 nm. The two step process is essential to prevent shortening of the top contact due to pin holes and deficiencies in the formation of the Al 2 O 3 layer . Both depositions were performed in vacuum conditions, and the samples were cooled to −5 °C in order to protect the organic layer from heat damages.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…The two step process is essential to prevent shortening of the top contact due to pin holes and deficiencies in the formation of the Al 2 O 3 layer. 19 Both depositions were performed in vacuum conditions, and the samples were cooled to −5 °C in order to protect the organic layer from heat damages. The deposition rate was 0.5 Å/s.…”

Section: ■ Experimental Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Mapping the Energy Band Structure of Nanocrystal Monolayers under Ambient Conditions

et al. 2013

View full text Add to dashboard Cite

With increasing demand for scale minimization of integrated circuit, nanostructures are likely to become primary components of future electronic devices. Selfassembled hybrid organic molecule−nanocrystal devices propose a prospective route for achieving this goal. In this type of devices, the characterization of the energy band structure of the semiconductor nanocrystal layers is of major importance. Recent works used scanning tunneling spectroscopy to measure locally the single nanocrystal band structure. These measurements are expensive, complicated, and usually done at low temperatures. In this work, we map the energy band structure of a monolayer using a simple hybrid device under ambient conditions. The ensemble band structure is similar to results achieved by scanning tunneling microscopy. In most cases, the energy band edges are wider due to the size distribution in consistence with photoluminescence results.

show abstract

Section: Experimental Methodsmentioning

confidence: 99%

Section: ■ Experimental Methodsmentioning

confidence: 99%

Mapping the Energy Band Structure of Nanocrystal Monolayers under Ambient Conditions

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Vacuum sublimation pentacene purification was performed in a three-zone tube furnace at a pressure of ~ 1x10 -5 mBar. Such four-time purified pentacene had previously provided OTFTs with higher field-effect mobility than a three-time purified pentacene from Sigma-Aldrich [31]. The transistors were completed by evaporating gold source and drain contacts and their cross-section is shown in The surface topography of the gate dielectric and pentacene was studied by atomic force microscopy (AFM) using the tapping mode.…”

Section: Fabrication Of Metal-insulator-metal Structures and Otftsmentioning

confidence: 99%

Dry growth of n-octylphosphonic acid monolayer for low-voltage organic thin-film transistors

Gupta¹,

Glesková²

2013

Organic Electronics

Self Cite

View full text Add to dashboard Cite

show abstract

Effect of substrate temperature on vapor-phase self-assembly of n-octylphosphonic acid monolayer for low-voltage organic thin-film transistors

Gupta¹,

Šutta

Lamprou

et al. 2013

Organic Electronics

View full text Add to dashboard Cite

N-octylphosphonic acid (C8PA) monolayer was self-assembled on aluminium oxide (AlOx) from vapour in vacuum, while the substrate temperature was varied between 25 and 150°C. The capacitance, water contact angle measurement, Fourier transform infrared (FTIR) spectroscopy, and atomic force microscopy (AFM) confirmed the presence of C8PA on AlOx for all growth temperatures. However, the structural and electrical properties of such monolayers depend on their growth temperature. The minimum surface roughness of 0.36 nm, the maximum water contact angle of 113.5°±1.4°, the lowest leakage current density of ~ 10-7 A/cm2 at 3 V, and the capacitance of 0.43 µF/cm2 were obtained for AlOx/C8PA bi-layers with C8PA deposited at 25°C. The elevated temperature led to increased surface roughness, decreased water contact angle, increased leakage current, inferior molecular ordering, and lower molecular coverage; while the effect on the chemisorption of the phosphonate was minimal. Methyl and methylene FTIR vibrations associated with C8PA aliphatic tails exhibited similar centre-peak wavenumbers to those observed for C8PA monolayers assembled from solutions, presenting a viable ‘dry’ alternative to the existing solution process. The substrate temperature applied during C8PA self-assembly also affected the parameters of pentacene thin-film transistors with AlOx/C8PA gate dielectrics. The increase in the growth temperature from 25 to 150°C decreased the field-effect mobility from 0.060 to 0.026 cm2/Vs and increased the threshold voltage from -1.19 to -1.38 V, while maintaining the off-current at or below 10-12 A and the subthreshold slope near 90 mV/decade

show abstract

Optimizing Pentacene Growth in Low-Voltage Organic Thin-Film Transistors Prepared by Dry Fabrication Techniques

Cited by 3 publications

References 19 publications

Mapping the Energy Band Structure of Nanocrystal Monolayers under Ambient Conditions

Mapping the Energy Band Structure of Nanocrystal Monolayers under Ambient Conditions

Dry growth of n-octylphosphonic acid monolayer for low-voltage organic thin-film transistors

Effect of substrate temperature on vapor-phase self-assembly of n-octylphosphonic acid monolayer for low-voltage organic thin-film transistors

Contact Info

Product

Resources

About