- Tytuł:
- Investigation of Local Trapping States in Organic Molecular Crystals by Method of Thermally Modulated Space-Charge Limited Current
- Autorzy:
-
Muzikante, I.
Silinsh, Ε. A. - Powiązania:
- https://bibliotekanauki.pl/articles/1933595.pdf
- Data publikacji:
- 1995-08
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
72.20.Jv
72.80.Le
73.50.Gr
73.61.Ph
73.40.Rw - Opis:
- The method of thermally modulated space-charge limited current has been used for studying local charge carrier trapping state energy spectra in vacuum evaporated thin films and Langmuir-Blodgett multilayers of different organic molecular crystals. In case of evaporated thin polycrystalline layers of pentacene four sets of local trapping states in energy range from E$\text{}_{t}$ = 0.35 to 0.06 eV were observed. In evaporated thin layers of dimethylaminobenzylidene indandione-1,3 five sets of trapping states from Ε$\text{}_{t}$ = 0.59 to 0.28 eV were detected. In the evaporated layers of indandione-1,3 pyridinium betaine only a single set of very shallow trapping states close to the conductivity level was observed. In the Langmuir-Blodgett multilayers of vanadyl phthalocyanine and indandione-1,3 pyridinium betaine the activation energy E$\text{}_{a}$ dependence on applied voltage U, E$\text{}_{a}$(U), for bulk conductivity is not step-like as in case of evaporated layers, but of rather complicated, oscillatory shape. Such character of the E$\text{}_{a}$(U) dependence may be explained by the specific quantum well structure of the Langmuir-Biodgett multilayers and spatially nonuniform trap distribution. However, for in-plane conductivity of indandione-1,3 pyridinium betaine films the E$\text{}_{a}$(U) dependence is step-like and two sets of trapping states at E$\text{}_{t}$ = 0.45 ± 0.03 eV and E$\text{}_{t}$ = 0.18 ± 0.03 eV were obtained. In case of bulk conductivity of the Langmuir-Blodgett layers the activation energy E$\text{}_{a}$ at sufficiently high electric fields drops down to zero and the charge carrier transport switches to a "trap-free" regime.
- Źródło:
-
Acta Physica Polonica A; 1995, 88, 2; 389-399
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł