| Autor: |
Hosoi, Kazukuni, Hirano, Akihiro, Tani, Tadaaki |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 12/15/2001, Vol. 90 Issue 12, p6197, 8p, 2 Charts, 7 Graphs |
| Abstrakt: |
Techniques of radiowave photoconductivity (A) and microwave photoconductivity with two synchronized light pulses (B) were used to study the dynamics of photocreated positive holes in AgBr microcrystals with adsorbed cyanine dyes as spectral sensitizers. It was revealed by technique A that positive holes were captured by the dyes with oxidation potential (E[sub ox]) less positive than 1.40 V versus the saturated calomel electrode within a few microseconds. In the light of the fact that E[sub ox] corresponds to the height of the highest occupied molecular orbital (HOMO) of a cyanine dye, it was concluded that the height of the HOMO of the dye with E[sub ox] of 1.40 V was equivalent to that of the top of the valence band of AgBr. It was revealed by techniques A and B that positive holes decayed as a result of their encounter with such irreversible traps as Ag centers after repetition of trapping and detrapping by adsorbed dye molecules many times in a period ranging from 10[sup -5] to 10[sup 4] s, depending on the height of the HOMO and the amount of dyes. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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