Photothermal deflection spectroscopy of polymer thin films

1995 ◽  
Vol 61 (2) ◽  
pp. 159-161 ◽  
Author(s):  
S. K. So ◽  
M. H. Chan ◽  
L. M. Leung
Keyword(s):  
Thin Films ◽  
Polymer Thin Films ◽  
Photothermal Deflection Spectroscopy ◽  
Photothermal Deflection

Photothermal deflection spectroscopy of polymer thin films

1995 ◽  
Vol 61 (2) ◽  
pp. 159-161 ◽  
Author(s):  
S. K. So ◽  
M. H. Chan ◽  
L. M. Leung
Keyword(s):  
Thin Films ◽  
Polymer Thin Films ◽  
Photothermal Deflection Spectroscopy ◽  
Photothermal Deflection

Light-Soaking Effects on Photoconductivity in a-Si:H Thin Films

1997 ◽  
Vol 467 ◽  
Author(s):  
E. Morgado ◽  
M. Rebelo da Silva ◽  
R. T. Henriques
Keyword(s):  
Thin Films ◽  
Defect Density ◽  
Light Exposure ◽  
Dangling Bond ◽  
Photothermal Deflection Spectroscopy ◽  
Spin Resonance ◽  
Photo Conductivity ◽  
Photothermal Deflection ◽  
Gap States ◽  
Induced Defects

ABSTRACTMetastable defects have been created by light exposure in thin films of a-Si:H. The samples have been characterized by Photothermal Deflection Spectroscopy, Electron Spin Resonance, dark- and photo-conductivity. The experimental results are consistent with numerical calculations with a recombination model involving band tails and one class of correlated dangling-bond states. The effects of light-soaking on the ligh intensity and defect density dependences of photoconductivity are reproduced by the calculations. The model allows to explain the experimental trends by changes in the electronic occupation of the gap states produced by light-induced defects.

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.

Optical properties of TiO2 thin films estimated by photothermal deflection spectroscopy

2003 ◽  
Vol 74 (1) ◽  
pp. 863-865 ◽  
Author(s):  
S. Ogawa ◽  
K. Mori ◽  
H. Natsuhara ◽  
T. Ohashi ◽  
R. Sakakiyama ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Tio2 Thin Films ◽  
Photothermal Deflection Spectroscopy ◽  
Photothermal Deflection

Optical properties of CdTe thin films studied by photothermal deflection spectroscopy

1983 ◽  
Vol 102 (3) ◽  
pp. 259-263 ◽  
Author(s):  
J.G. Mendoza-Alvarez ◽  
B.S.H. Royce ◽  
F. Sánchez-Sinencio ◽  
O. Zelaya-Angel ◽  
C. Menezes ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Photothermal Deflection Spectroscopy ◽  
Cdte Thin Films ◽  
Photothermal Deflection

Optical Spectra of Fullerenes: C60 a new amorphous semiconductor?

1992 ◽  
Vol 270 ◽  
Author(s):  
Andrew Skumanich
Keyword(s):  
Thin Films ◽  
Carbon Films ◽  
Amorphous Semiconductor ◽  
Amorphous Semiconductors ◽  
Wide Energy Range ◽  
Optical Absorption Spectra ◽  
Optical Gap ◽  
Photothermal Deflection Spectroscopy ◽  
Wide Energy ◽  
Photothermal Deflection

ABSTRACTThe optical absorption spectra for thin films of sublimed C60 and C70 are presented. Both transmission spectroscopy and photothermal deflection spectroscopy are used to obtain the spectrum over a wide energy range (0.4 to 6.2 eV) for the same film. The optical gap varies for the different fullerenes. The value for C60 is ∼ 1.6 eV and the corresponding transition appears to be optically forbidden given the weakness of the absorption. Structure is observed on the “gap edge” which can be attributed to vibronic transitions. The gap region can be described in terms used for amorphous semiconductors, having features such as an Urbach edge, and sub-gap defect absorption. The similarity suggests that the nature of fullerene thin films may be analogous to amorphous silicon and carbon films. These films have both a molecular and an amorphous semiconductor nature.

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