Morphology of α-hexathienyl thin-film-transistor films

1995 ◽  
Vol 10 (11) ◽  
pp. 2958-2962 ◽  
Author(s):  
A.J. Lovinger ◽  
D.D. Davis ◽  
R. Ruel ◽  
L. Torsi ◽  
A. Dodabalapur ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
High Temperature ◽  
Electron Diffraction ◽  
Thin Film Transistor ◽  
High Temperature Annealing ◽  
Atomic Force ◽  
Normal Orientation ◽  
Electronic Performance ◽  
High Temperature Polymorph

We have studied the morphology of thin films of α-hexathienyl (α-6T), a hexamer of thiophene that is a very promising material for thin-film-transistor applications. Using electron- and atomic-force microscopies, we found that on both rigid (Si/SiO2 and glass) and flexible (polyimide) substrates, evaporated films show an apparently random, polycrystalline morphology. The crystals are lamellar, ca. 100-200 nm in lateral dimensions and 15-30 nm in thickness, and exhibit irregular boundaries. Nevertheless, electron-diffraction evidence from such films indicates that the constituent molecules are deposited preferentially end-on and assume a normal or nearly normal orientation with respect to their substrates. Rapid high-temperature annealing causes growth of much larger (μm-sized) crystalline grains and a partial transformation to a high-temperature polymorph; however, this process leads to formation of gaps in the film, which may cause deterioration of electronic performance.

JOSEPHSON JUNCTION USING A CROSSED CONTACT OF SUPERCONDUCTING Bi(Pb)-Sr-Ca-Cu-O THIN FILM WITH 110 K-PHASE

1991 ◽  
Vol 05 (14n15) ◽  
pp. 985-992
Author(s):  
S. HIGO ◽  
M. IMAI ◽  
Y. HAKURAKU ◽  
I. KAWANO ◽  
T. OGUSHI
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
High Temperature ◽  
Magnetron Sputtering ◽  
Induced Current ◽  
High Temperature Annealing ◽  
Dc Magnetron Sputtering ◽  
Single Junction ◽  
Assisted Tunneling ◽  
Current Steps

Bi 1.75 Pb 0.17 Sr 2 Ca 2.1 Cu 3.2 O y thin films with zero resistivity at 115 K, were prepared by dc magnetron sputtering and subsequent high-temperature annealing. Josephson bridges were fabricated by crossed contact of two cleaved planes of the thin films. Self-induced current steps and multi photon-assisted tunneling currents due to quasi-particles tunneling across the oxide gap barriers were observed. It was proved that the formation of the oxide gap barriers was due to oxidation of the Cu component and the extrication of Ca near the crossed contact of the thin film by soaking the thin film in liquid nitrogen. It seems possible to fabricate smaller bridge with a single junction by the use of thinner as-grown films with smoother surfaces.

High Temperature Annealing Behaviors of Luminescent Siox:H Films

1999 ◽  
Vol 560 ◽  
Author(s):  
Zhixun Ma ◽  
Xianbi Xiang ◽  
Shuran Sheng ◽  
Xianbo Liao ◽  
Chunlin Shao ◽  
...  
Keyword(s):  
High Temperature ◽  
Absorption Edge ◽  
Optical Transition ◽  
Stokes Shift ◽  
Transition Process ◽  
Ir Absorption ◽  
High Temperature Annealing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Si Nanocrystals

ABSTRACTThe effects of high temperature annealing on the microstructure and optical properties of luminescent SiOx:H films have been investigated. Micro-Raman scattering and IR absorption, in combination with atomic force microscopy (AFM), provide evidence for the existence of both a-Si clusters in the as-grown a-SiOx:H and Si nanocrystals in the 1170°C annealed films. The dependence of optical coefficients (μ) on photon energy (hv) near the absorption edge (Eg) is found to follow the square root law: (μhv)½ μ (Eg – hv), indicating that nano-Si embedded in Si02 is still an indirect material. A comparison of the deduced absorption edge with the PL spectra shows an obvious Stokes shift, suggesting that phonons should be involved in the optical transition process.

scholarly journals Tip-Based Nanomachining on Thin Films: A Mini Review

2021 ◽  
Author(s):  
Shunyu Chang ◽  
Yanquan Geng ◽  
Yongda Yan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Data Storage ◽  
Three Dimensional ◽  
Maintenance Cost ◽  
Two Dimensional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current State ◽  
Two Dimensional Materials

AbstractAs one of the most widely used nanofabrication methods, the atomic force microscopy (AFM) tip-based nanomachining technique offers important advantages, including nanoscale manipulation accuracy, low maintenance cost, and flexible experimental operation. This technique has been applied to one-, two-, and even three-dimensional nanomachining patterns on thin films made of polymers, metals, and two-dimensional materials. These structures are widely used in the fields of nanooptics, nanoelectronics, data storage, super lubrication, and so forth. Moreover, they are believed to have a wide application in other fields, and their possible industrialization may be realized in the future. In this work, the current state of the research into the use of the AFM tip-based nanomachining method in thin-film machining is presented. First, the state of the structures machined on thin films is reviewed according to the type of thin-film materials (i.e., polymers, metals, and two-dimensional materials). Second, the related applications of tip-based nanomachining to film machining are presented. Finally, the current situation of this area and its potential development direction are discussed. This review is expected to enrich the understanding of the research status of the use of the tip-based nanomachining method in thin-film machining and ultimately broaden its application.

scholarly journals Thin-film chemical expansion of ceria based solid solutions: laser vibrometry study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hendrik Wulfmeier ◽  
Dhyan Kohlmann ◽  
Thomas Defferriere ◽  
Carsten Steiner ◽  
Ralf Moos ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
High Temperature ◽  
Film Thickness ◽  
Solid Solutions ◽  
Low Voltage ◽  
Excitation Frequency ◽  
Dimensional Change ◽  
Potential Core ◽  
Chemical Expansion

Abstract The chemical expansion of Pr0.1Ce0.9O2–δ (PCO) and CeO2–δ thin films is investigated in the temperature range between 600 °C and 800 °C by laser Doppler vibrometry (LDV). It enables non-contact determination of nanometer scale changes in film thickness at high temperatures. The present study is the first systematic and detailed investigation of chemical expansion of doped and undoped ceria thin films at temperatures above 650 °C. The thin films were deposited on yttria stabilized zirconia substrates (YSZ), operated as an electrochemical oxygen pump, to periodically adjust the oxygen activity in the films, leading to reversible expansion and contraction of the film. This further leads to stresses in the underlying YSZ substrates, accompanied by bending of the overall devices. Film thickness changes and sample bending are found to reach up to 10 and several hundred nanometers, respectively, at excitation frequencies from 0.1 to 10 Hz and applied voltages from 0–0.75 V for PCO and 0–1 V for ceria. At low frequencies, equilibrium conditions are approached. As a consequence maximum thin-film expansion of PCO is expected due to full reduction of the Pr ions. The lower detection limit for displacements is found to be in the subnanometer range. At 800 °C and an excitation frequency of 1 Hz, the LDV shows a remarkable resolution of 0.3 nm which allows, for example, the characterization of materials with small levels of expansion, such as undoped ceria at high oxygen partial pressure. As the correlation between film expansion and sample bending is obtained through this study, a dimensional change of a free body consisting of the same material can be calculated using the high resolution characteristics of this system. A minimum detectable dimensional change of 5 pm is estimated even under challenging high-temperature conditions at 800 °C opening up opportunities to investigate electro-chemo-mechanical phenomena heretofore impossible to investigate. The expansion data are correlated with previous results on the oxygen nonstoichiometry of PCO thin films, and a defect model for bulk ceria solid solutions is adopted to calculate the cation and anion radii changes in the constrained films during chemical expansion. The constrained films exhibit anisotropic volume expansion with displacements perpendicular to the substrate plane nearly double that of bulk samples. The PCO films used here generate high total displacements of several 100 nm’s with high reproducibility. Consequently, PCO films are identified to be a potential core component of high-temperature actuators. They benefit not only from high displacements at temperatures where most piezoelectric materials no longer operate while exhibiting, low voltage operation and low energy consumption.

Thin Film Morphology and GrowthMechanism of Pentacene Thin Film Using Low-Pressure Organic Vapor Deposition

2003 ◽  
Vol 769 ◽  
Author(s):  
Seong Deok Ahn ◽  
Seung Youl Kang ◽  
Yong Eui Lee ◽  
Meyoung Ju Joung ◽  
Chul Am Kim ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Vapor Deposition ◽  
Thin Film Transistor ◽  
Low Pressure ◽  
Chamber Pressure ◽  
Film Morphology ◽  
Organic Thin Film ◽  
Organic Thin Film Transistor ◽  
Organic Vapor

AbstractWe have investigated the growth mechanism and thin film morphology of pentacene thin films by the process of low-pressure gas assisted organic vapor deposition (LP-GAOVD). As the source temperature, flow rate of the carrier gas, substrate temperature and chamber pressure were varied, the growth rate, morphology and grain size of the films were differently obtained. The electrical properties of pentacene thin films for applications in organic thin film transistor and electrophoretic displays were discussed

scholarly journals Comparative Study of ZnO Thin Films Grown on Quartz Glass and Sapphire (001) Substrates by Means of Magnetron Sputtering and High-Temperature Annealing

2019 ◽  
Vol 9 (21) ◽  
pp. 4509
Author(s):  
Weijia Yang ◽  
Fengming Wang ◽  
Zeyi Guan ◽  
Pengyu He ◽  
Zhihao Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Magnetron Sputtering ◽  
Comparative Study ◽  
Quartz Glass ◽  
Photoelectron Spectroscopy ◽  
Zno Thin Films ◽  
High Temperature Annealing ◽  
X Ray ◽  
Glass Substrates

In this work, we reported a comparative study of ZnO thin films grown on quartz glass and sapphire (001) substrates through magnetron sputtering and high-temperature annealing. Firstly, the ZnO thin films were deposited on the quartz glass and sapphire (001) substrates in the same conditions by magnetron sputtering. Afterwards, the sputtered ZnO thin films underwent an annealing process at 600 °C for 1 h in an air atmosphere to improve the quality of the films. X-ray diffraction, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectra, photoluminescence spectra, and Raman spectra were used to investigate the structural, morphological, electrical, and optical properties of the both as-received ZnO thin films. The ZnO thin films grown on the quartz glass substrates possess a full width of half maximum value of 0.271° for the (002) plane, a surface root mean square value of 0.50 nm and O vacancies/defects of 4.40% in the total XPS O 1s peak. The comparative investigation reveals that the whole properties of the ZnO thin films grown on the quartz glass substrates are comparable to those grown on the sapphire (001) substrates. Consequently, ZnO thin films with high quality grown on the quartz glass substrates can be achieved by means of magnetron sputtering and high-temperature annealing at 600 °C.

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