Influence of Air Exposure on Photocarrier Generation in Amorphous and Phase II Thin Films of Titanyl Phthalocyanine

2018 ◽  
Vol 122 (14) ◽  
pp. 7731-7736 ◽  
Author(s):  
Keitaro Eguchi ◽  
Yoshiaki Imai ◽  
Michio M. Matsushita ◽  
Kunio Awaga
Keyword(s):  
Thin Films ◽  
Phase Ii ◽  
Air Exposure ◽  
Titanyl Phthalocyanine

Photovoltaic Behaviour of Titanyl Phthalocyanine Thin Films and Titania Bilayer Films

2008 ◽  
Vol 268 (1) ◽  
pp. 57-60 ◽  
Author(s):  
M. Drabik ◽  
A. M. Zachary ◽  
Y. Choi ◽  
J. Hanus ◽  
J. Tousek ◽  
...  
Keyword(s):  
Thin Films ◽  
Bilayer Films ◽  
Titanyl Phthalocyanine

Optical stability of small-molecule thin-films determined by Photothermal Deflection Spectroscopy

2009 ◽  
Vol 1154 ◽  
Author(s):  
Marco Stella ◽  
Monica Beatriz Della Pirriera ◽  
Joaquim Puigdollers ◽  
Joan Bertomeu ◽  
Cristobal Voz ◽  
...  
Keyword(s):  
Thin Films ◽  
Absorption Coefficient ◽  
Small Molecule ◽  
Bulk Heterojunctions ◽  
Absorption Bands ◽  
Absorption Region ◽  
Air Exposure ◽  
Photothermal Deflection Spectroscopy ◽  
Photothermal Deflection ◽  
P Type

AbstractIn this paper the optical absorption properties of n-type C60 and PTCDA, and p-type CuPc small molecule semiconductors are investigated by optical transmission and Photothermal Deflection Spectroscopy (PDS). The results show the usual absorption bands related to HOMO-LUMO transitions in the high absorption region of the transmission spectra. PDS measurements also evidences exponential absorption shoulders with different characteristic energies. In addition, broad bands in the low absorption level are observed for C60 and PTCDA thin-films. These bands have been attributed to contamination due to air exposure. In order to get deeper understanding of the degradation mechanisms single and co-evaporated thin-films have been characterized by PDS. The dependence of the optical coefficient on exposure to light and air have been studied and correlated to the structural properties of the films (as measured by X-Ray Diffraction Spectroscopy). The results show that CuPc and PTCDA are quite stable against light and air exposure, while C60 shows important changes in its absorption coefficient. The bulk heterojunctions show stability in agreement with what observed for single layers, since the absorption coefficient of CuPc:PTCDA is almost not altered after the degradation treatments, while CuPc:C60 shows changes for low energy values.

Titanyl Phthalocyanine (TiOPc) Organic Thin Film Transistors With Highly π-π Interaction

2010 ◽  
Vol 1270 ◽  
Author(s):  
Huang-Ming Philip Chen ◽  
Yung-Hsing Chen ◽  
Bo-Ruei Lin
Keyword(s):  
Thin Film ◽  
Crystal Structure ◽  
Substrate Temperature ◽  
Phase Ii ◽  
Amorphous Powder ◽  
Organic Thin Film ◽  
Crystal Forms ◽  
Triclinic Phase ◽  
P Type ◽  
Titanyl Phthalocyanine

AbstractThe objective of this research is to obtain uniform vacuum-deposition triclinic phase II crystal of titanyl phthalocyanine (α-TiOPc) films from various TiOPc crystal forms. The crystal structure and morphology of vacuum-deposited TiOPc films can be manipulated by deposition rate and substrate temperature. Crystal structure was determined by X-ray diffraction (XRD). Thin film morphology was analyzed by scanning electron microscope (SEM). Highly ordered α-TiOPc film with an edge-on molecular orientation was deposited on octadecyltrichlorosilane (OTS) treated Si/SiO2 surface. All TiOPc crystal forms, such as amorphous, α and γ phases, provided the triclinic phase II crystal of TiOPc. The full width at half maximum (FWHM) of the peak at 7.5 degree in XRD spectra was 0.23, 0.27 and 0.29 for γ, α and amorphous powder when substrate temperature maintained at 180°C, respectively. The FWHM of the 7.5 degree peak can be achieved 0.22 deposited from all crystal forms at elevated temperature higher than 220°C. The α-TiOPc deposition film exhibited an excellent p-type semiconducting behavior in air with dense packing structure due to the close π–π molecular packing. The devices, field-effect mobility range from 0.02 to 0.26 cm2/V s depending on various process parameters. The on/off current ratio (Ion/Ioff) is over 105. The TiOPc OTFTs will be applied as multi-parameter gas sensor in the near future.

Polymorphism and Phase Control in Titanyl Phthalocyanine Thin Films Grown by Supersonic Molecular Beam Deposition†

2007 ◽  
Vol 111 (49) ◽  
pp. 12550-12558 ◽  
Author(s):  
Nicola Coppedè ◽  
Tullio Toccoli ◽  
Alessia Pallaoro ◽  
Fabrizio Siviero ◽  
Karsten Walzer ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Beam ◽  
Phase Control ◽  
Supersonic Molecular Beam ◽  
Molecular Beam Deposition ◽  
Beam Deposition ◽  
Titanyl Phthalocyanine

Photoelectrochemical and spectroscopic characterization of thin films of titanyl phthalocyanine: comparisons with vanadyl phthalocyanine

1987 ◽  
Vol 91 (22) ◽  
pp. 5646-5651 ◽  
Author(s):  
T. J. Klofta ◽  
J. Danziger ◽  
P. Lee ◽  
J. Pankow ◽  
K. W. Nebesny ◽  
...  
Keyword(s):  
Thin Films ◽  
Spectroscopic Characterization ◽  
Titanyl Phthalocyanine

Low Temperature Chemical Vapor Deposition of Titanium Nitride Thin Films With Hydrazine and Tetrakis-(dimethylamide)Titanium

1999 ◽  
Vol 606 ◽  
Author(s):  
Carmela Amato-Wierda ◽  
Edward T. Norton ◽  
Derk A. Wierda
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Air Exposure ◽  
Temperature Growth ◽  
Low Temperature Growth ◽  
Reducing Ability ◽  
Tin Thin Films

AbstractHydrazine and tetrakis-(dimethylamido)titanium have been used as precursors for the low temperature chemical vapor deposition of TiN thin films between 50°C and 200°C at growth rates between 5 to 35 nm/min. At hydrazine to TDMAT ratios of 50:1 and 100:1 the resulting films show an increase in the Ti:N ratio with increasing deposition temperature. They contain 2% carbon, and varying amounts of oxygen up to 36% as a result of diffusion after air exposure. The low temperature growth is improved when hydrazine-ammonia mixtures containing as little as 1.9% hydrazine are used. Their Ti:N ratio is almost 1:1 and they contain no carbon or oxygen according to RBS. The TiN films grown from pure hydrazine or the hydrazine-ammonia mixture have some crystallinity according to x-ray diffraction and their resistivity is on the order of 104µω cm. The low temperature growth is attributed to the weak N–N bond in hydrazine and its strong reducing ability. In these films, the Ti:N ratio is approximately 1:1.

Properties of Si/Cs/O nanocluster thin films with negative electron affinity

1999 ◽  
Vol 558 ◽  
Author(s):  
L. N. Dinh ◽  
W. McLean ◽  
M. A. Schildbach ◽  
M. Balooch
Keyword(s):  
Thin Films ◽  
Field Emission ◽  
Electron Affinity ◽  
Electron Emission ◽  
Field Electron Emission ◽  
Negative Electron Affinity ◽  
Air Exposure ◽  
Field Electron ◽  
Emission Microscopy ◽  
Background Gas

ABSTRACTThin films of Si/Cs/O nanoclusters have been synthesized by the technique of supersaturated thermal vaporization of Si and Cs in an oxygen background gas. These films, which were deposited onto conducting or semiconducting substrates, exhibit negative electron affinity (NEA) as evidenced by ultraviolet photoemission spectroscopy (UPS). Photo and field electron emission properties of these nanocluster films were investigated with photo-electron emission microscopy (PEEM), field electron emission microscopy (FEEM), and current-voltage measurements. Flat cathodes covered with thin films of Si/Cs/O nanoclusters exhibited high current outputs and low turn-on fields. The films' NEA is unaffected by air exposure and is stable to high temperature annealing (550 TC). A field emission display unit with a simple diode structure containing a flat cathode coated with a patterned thin film of Si/Cs/O nanoclusters has also been built to demonstrate the potential application of this material in cold cathode electron emitting devices, particularly field emission flat panel displays.

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