熱刺激電流로 LB膜의 分極測定 = Measurements of Polarization in LB Films by Thermally Stimulated Current

다국어 초록 (Multilingual Abstract)

Langmuir-Blogett(LB) films of arachic acid and TCNQ (tetracyanoquinodimethane) were prepared in the sample of Al/LB film/A1 type where Al are electrodes, and polarization in LB film and dipolar moment of molecules in the films were measured by thermally stimulated current. It was determined from the direction of the thermally stimulated depolarization current that the hydrophilic radical was positive polarity in molecular dipoles of both LB films. Initial rise in thermally stimulated depolarization current was measured on LB films of TCNQ with alkyl radical (C_(12) TCNQ), then the activation in the current vs. temperature characteristics was determined. Dipolar moment of C_(12)TCNQ molecule in LB film was calculated by using the value of the activation energy and Lorentz local field, then it was evaluated at about 13 debyes.
Al₂O₃ layer(about 30A thickness) was yielded on the Al electrode by natural oxidation in air. According to the cooperation of Al₂O₃ dielectric layer and the polarization of C_(12)TCNQ LB film, the macroscopic electrical field was yielded in LB film and Al₂O₃ layer. Calculating the electrical field by the polarization' due to dipolar moment of C_(12)TCNQ molecule, the field strength in C_(12)TCNQ LB films was evaluated at about 1 × 10^(8)~5 × 10^(6)V/cm. The field strength is decreased in increasing of number of LB monolayer and such a high field will be important in the electrical characteristics of LB films. LB film of C_(12)TCNQ is Z-type, so rather large polarization in the LB film will be yielded and high. electrical field will be also generated, comparing with the case in Y-type LB film as arachic acid film.

목차 (Table of Contents)

• 1. 서론
• 2. 측정방법
• 2-1. 시료
• 2-2. 측정회로
• 3. 측정 결과
• 3-1. 膜累積數와 靜電容量
• 3-2. arachic acid·LB膜 (Y型)
• 3-3. C_(12)TCNQ·LB膜(Z型)
• 4. 熱刺激說分極電流의 活性化에너지
• 5. Cl_(12)TCNQ의 能率과 그 LB膜內의 電界
• 6. 검토
• 7. 결론